I habitually brutally roast people on complete accident when they say things like this to me. I don't mean to, it just comes out like a sneeze or a flinch (but I intimately feel terrible afterwards). So if someone told me my work was trash, personally, I'd probably verbally make them regret the day they slid from their mother's womb. Though I certainly don't recommend doing it. That just opens up a whole can of worms.
The best thing to do is just remember that some people can't grasp concepts the same way you or your readers do, or perhaps they have different tastes. So if one sour patch kid tells you something like that with a complete lack of constructive criticism, don't take it to heart. You can ignore it and be the bigger person. There's a chance they just don't like it because of differing personal preferences....or maybe they're just an idiot.