I wouldn't really say anything as I dislike confrontation. I would probably believe them and possibly even thank them for being honest, then just never talk to them again. (It depends on their relationship with me).
I kind of take comments with a grain of salt because I think if someone is trying to communicate something meaningful they will usually do it in a space where other people aren’t going to engage and upvote and receive attention for posting their opinion. That doesn’t necessarily make it invalid but people can and do opt for more private means of communication like DMs or email when it comes to matters that could be sensitive.
But if someone is just trying to push my buttons I’d ignore it. Those people want you to engage and react in one way or another and if you just refuse to give them the time of day they’ll usually just go away eventually.
"Aren´t we all trash in some way?"
No, but seriously, either I ignore the comment or just give the "K" reply.
Kill them with kindness. I try to be very sweet and polite, and sometimes that just riles the person up more, which is a good indicator they're more interested in trying to get a rise out of you than give real feedback.
I generally might respond with something along the lines of "I'm sorry you feel that way/I hope you find something more to your taste." Though I don't mind engaging in the criticism if the other party is actually interested in talking and not just talking crap.
If it's a person I know in real life I'm WAY more sensitive though. I'd probably cry? 
I'd pity them and just smile. What else is there to be done?
Every story has his flaws. And every story has its good points. There are ways to express one's opinions in a constructive manner, in a manner that would permit for the author to elevate his work to the next level.
However, using words with negative connotations, such as trash, is certainly not one such manner. In fact, using such words generally denotes unhappiness, irritability. It implies an emotional response to something. That something may not be an author's story. In fact, it most probably isn't. When such words are used, there is a inherent desire to hurt the receiving person. Insults do not come from a happy place. Misery likes company. Unhappy people sometimes want to make others unhappy too.
The truth is, when I consider a work unworthy of my time (gosh, this sounds mean), I do not go to the trouble of commenting at all, I simply banish it from my thoughts and move on. But someone was so irked, triggered, as we like to say, by something about that author's behavior, story or by nothing at all, really, that that someone actually took the time, even if it is 10 seconds of his life, to a write a mean comment. Those are 10 seconds of his life he will never get back.
Damn, I am sorry for that person just thinking about it ...
Honestly I would get very offended hahaha. but I would act like I don't care, after I would get sooo angry 
, then I would be all worried, "what if they are right?"
and finally I would cry and feel terrible. I am very sensitive 
But I would keep writing and drawing, what else can I do! It's what I love!!
It really depend whether the person criticizing ACTUALLY said the story is trash, or if the person receiving the criticism INTERPRETED as 'this person says my story is trash', because the criticism is harsh.
First case: I would have pretty much no reaction. I don't care. 'Not constructive: next!'. I may not be very confident in my beginner comic skills, but there is no way there is nothing more to say than 'it's trash'. I think any work where the creator put some effort worth... more effort than 'it's trash' as a critic.
Second case: I personally love harsh constructive criticism. Also love nice constructive criticism. As long as it does the job of making me think, evolve and reconsider, I love it.
But I understand sometimes, people need things to be said more nicely. So I would say, if someone is in this situation of receiving very harsh, but constructive criticism, and is upset and depressed by it: remember that for some people, criticizing harshly means they think you have what it takes to be much better; that they have faith in you and think you can improve significantly. Now, obviously, that is not what's behind all harsh constructive criticism. But I think it worth remembering, that it's not necessarily an aggression. Sometimes, ot's a compliment.
If it was online, I'd probably ignore it. If it happened IRL, I'd probably laugh awkwardly and leave.
People leave comments like that to get a rise out of people--if you respond, it gives their argument validity, it gives them a rush, it encourages their bad and childish behavior. So, the best response, IMO is no response and a firm block.
If it's just constructive criticism I might not block but I probably won't bother responding. Too many people get waaay too wrapped up in webcomics and expect them to be this high art when it's like...yo I'm making this for free. You get what you get.
But tbh all of my comments on my comic have been very nice. I think mean comments is mostly a problem for people who have a very large following.
I really dont have time to waste on opinionated arguments. If someone were to say it, and their opinion doesnt matter to me, I basically shrug & keep it moving. In this day & age there are too many folks who think their opinion holds some type of weight or value to it; even more so when they arent even a student in the respective field. Then there are others who think that for a work to be "to a standard" it has to have "this element" and/or "that element" and if it doesnt have these things then the work isnt "to standard"- that is bullshit as well...
well, some of my reader said i need to improve my grammar and it helped me a lot so i often do a improvise to my chapter.
right now im working on a Light Novel and i enjoy it so much.
critiques is needed even sometime deep in your heart is hur.t
If they can't muster to tell why exactly they think my story is trash, i would roll on the floor laughing. Too many people these days think they're entitled to an opinion while forgetting what it takes to form one.
If they break down why my story is trash, i'd feel a bit sad.
Tbh, I know my writing is trash. That's why I'm making an experimental comic and posting it on line for free. I'm just learning. If I was great at writing and art, I'd probably try and sell it or something.
So, I'd probably just say 'Thanks for pointing out the obvious! What do you think about my art though?'
If someone said my art or character designs were trash, that's what would upset me more. I know I've got a looonnggg way to go in my artistic journey, but drawing really is my passion, so I'd be upset that they couldn't actually say something constructive, or see any value in my art at all.
I'd thank them. I'd make an effort to not sound too sarcastic, though I might throw in a, "Well, bless your heart."
I might ask for suggestions on how I should write, and ask them to cite a specific area that needs improvement. If they can't do that, reframing their trash review as a constructive critique, I just shrug it off. Maybe I'd silently stew for a bit about useless criticism.
First, I ask them to elaborate. 
Communication, communication, communication...
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If they can put their experience into words in a more constructive way, I thank them for that.
Not everyone knows how to give a good critique, and even good critique can hurt. But it's helpful to know what people think.
But we also have to keep in mind that not everyone is going to like what we do, regardless of how well they may or may not be expressing themselves. Tastes differ.
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If they just keep going in the same way, being hateful etc, I'll tell them that I hope things take a turn for the better for them soon. Which I genuinely mean. It's not a snide remark from my side. I believe that people who seek attention this way, or feel the need to use the comment section as an outlet for negativity, are struggling with something - one way or another.
I'm not saying this justifies their behaviour, or serves as an excuse.
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At the end of the day, you should never feel like you have to deal with this behaviour if you can't / don't want to. Check in with yourself, and put your own mental health first. <3
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The only approach I don't feel leads anywhere, is answering negativity with negativity.
Then it is better to block/ignore and move on.
I have had people tell me that. It stings for a while and then I move on. I can't change their minds and they're obviously not part of my target demography then.
I've also come to learn if they can't elaborate on why they think it's trash and how to make the novel not trash, then I don't really care about what they have to say. They're obviously not offering an actual critique, but are most likely just bored or something. So meh.
There will be always people like that. Trolling and hurting people for their own amusement.
And then sometimes it can even come in the form of friendly advice.
Years ago someone from my close family came to me while I was drawing. She looked at my art, watched as I drew, and then said: "You know sweetie, no matter how hard you try, how much you practice, you will never be a good artist."
Feels like a kick to the stomach even after all this time.
What you can do is ignore these remarks, and keep on going. The more you practice, the better you are.
"I know, but at least I didn't write a fanfic BDSM story that took advantage of an existing fanbase and turned it into my own sickening play of how badly defined consent is during the act of sex 
and then write three books of this fanfic, and sell it to the masses, and let them eat that up."
Spot on; I couldn't have said this better myself.
Criticism that points out a specific issue should always be considered--even if it's vague (Your story is boring)--otherwise forget about it.
That's a very good approach (the Bible says it's like pouring hot coals on their head 
). If you react in a negative way you devalue your reputation and make yourself seem a lot less professional.
Wow, that's a harsh thing to hear I bet. In my opinion anyone can be a good artist if they put the time and effort into it (even if some people have more raw natural talent).
11 months later
Once this writer I met on discord wanted some help or something so I offered. And halfway through the conversation she was like I don't think you are a good writer. I was like okkkay, awkwarddd
8 days later
You just take it and break it. Keep working harder until your writing is good enough to publish. As humans, we tend to take harsh criticism to heart and despite the 100 people enjoying it, the 1 person that does not is the one comment we remember. So, it's good to tune most of that out unless it's good tips (like how to better incorporate conflict in your stories). But, if the person likely said just "this is trash" with no explanation as to why, then that's as useless a comment as it gets. A better one would be "your writing is at a good start, but here are some links on how to polish it up and get more traction."
I'd ignore I think. While not perfect I love what I do and it makes me proud to be able to finish stories not matter the quality. I know there is room for improvement, I don't need someone to tell me and especially not in such rude way.
The ideal choice would be to ignore them, but it's not what I would do.
I would ask them what was so bad about it and try to get constructive criticism out of them. If it doesn't work and I feel like they're just trolling, then I would ignore them.
It depends from who the criticism comes from.
But mostly, I just try to follow this advice: 'don't take criticism from someone who you wouldn't take advice either'.
I think I'd reply and politely ask them to elaborate. sure, it doesn't seem like they're here to give any constructive criticism, but who knows? maybe I can squeeze some outta them anyway.
10 days later
eh, its happened before
ask them how i can improve and If they dont have anything constructive to say then move on.
I'm always working to make my writing better, since im not the most confident in my writing i want it to be equal with my art.
If it is constructive, lean into it and try to gather how others might perceive my writing. If it is literal "ur writing suks", then I'm gonna go on my way and continue to learn what I need to in order to get better.
I'm pretty confident in my ability to write and tell stories. I might ask what their reasoning is, in case they had a good reason. If they didn't, I'd probably tell them, "Not everything is for you. I hope you find a story more to your liking!"
Or I'd ignore it, unless it became a consistent "rude comment on multiple chapters" issue.
Personally... I would reply overly positive to them, like they had just given me kind worded constructive criticism... usually that makes them apologize.
Then I would look at what they were calling trash, they had a reason for saying it, (not saying they actually did in your case) (but if it was ME) i would look into writing workshops. I am still always looking at ways to improve my writing, workshops and lectures are a great resource.
And lastly i would reassure myself that no matter what anyone else believes about your writing, you had the courage and creative mind to start writing. You are trying and giving it your all.
No one can make you feel something or someway unless you let them, so don't let them! <3
AGAIN YOU DON'T HAVE TO DO ANYTHING TO CHANGE YOUR WRITING, THAT PERSON WAS BEING AN A$$
9 days later
I would just ignore, because I already say even worse things about my art, so I don't need another me.
If they were actually paying me full time to do it LOL until then, they can shove their opinion up their ass 
