Maybe the real cringe is criticizing people for things they like that don't affect you in any way.

There's ways to disagree and express dislike without being a twat, dude..

If you think this is "how most people are with societal filters stripped away" you may be projecting a bit. Sure, there's plenty of dishonesty in the world, and a lot of that dishonesty is done in the name of social etiquette. That said, we humans are social animals that have formed communities together since the dawn of our very species, and I don't see how the social structures we innately form could do so if we were all sociopathic twats to each other 24/7. Not all kindness or politeness is faked, man.

Now, would I want people to be more honest with me? Hell yes. I would rather get an honest, scathing review on my writing than dishonest gentle pats on the back; I need the former if I'm going to improve. That said, there's little flaming me will do other than tell me the reviewer is a cunt. Telling me "This character's plotline was rushed and didn't pay off" is criticism I need to hear – harsh, but honest. Telling me "You can't write characters for shit and you should kill yourself, faggot" just tells me you have misplaced aggression issues and that listening to you is neither good for my health nor a boon to my learning, and in the end, it's as worthless as the pat on the back.