No, I don't think this is something that is "suddenly" happening that didn't happen before. I do have a problem when people feel the need to contact the creator directly and tell them what they don't like, which I think is more common now with social media, but reviews? I dunno, I think negative reviews are the APPROPRIATE response to being unhappy with a work. You just don't need to tell me if you don't like my stuff!
It's not common, but I have seen complaints about my work in other places. If what they don't like is something I'm proud of and believe is good, it's very easy to brush aside -- this just isn't the comic for them. If it's something I wasn't sure about or was afraid of messing up, it hurts to read. I wouldn't tell a creator "haha get a thicker skin!" but I would say it's important to be able to move on, or to just not read unkind complaints if they get to you. I talked to a friend when someone said something that got under my skin, and after that I was okay. And I save my readers' kindest comments to remind myself how much my work meant to someone.
I look at it a little differently!
There was one particular webcomic that a lot of my peers in college hated. I've seen some pretty intense negative reviews, and when I checked it out myself, I can see why. The strip updated daily but the art did not seem to improve over the course of years. The storylines, I was told, were clumsy and poorly handled; the characters, they said, were a poorly-written mess. My peers found it frustrating that a comic like that should be so popular, but I was inspired.
That comic was hated, sure, but it also had so many devoted, genuine fans. There were people who related to the poorly-written characters and were excited about the clumsy storylines. If that comic can have so much wrong with it and still resonate with people.... that means my work can resonate with someone too, even if I mess up. Even with all that negative press, this guy still had so many people who were grateful for his comic and loved his work unironically. That's really hopeful and cool, to me!
There are so many properties where it feels like "everyone" hates them, but that isn't true! "Everyone" doesn't hate Twilight; thousands of people love it, flaws and all. The trick is, who are you focusing on?