I dunno. I get "your protag is an asshole so I don't like him!!! that is bad!!!" sometimes... but bc it's a story about growth and redemption it kind of makes me think... "missed the point maybe?" I mean, not all protags have to be super likeable lawful good types. Sometimes they reflect something in ourself we don't like.
I've also been told my art is bad because, and I quote, "You're afraid to go fully weeaboo with it." which is the most redundant thing I've ever heard. I'm an asian kid living in the UK. Of course it feels semi-asian and semi-western. That isn't a criticism it's just an observation. I just kind of felt like the person was wasting my time and not helping...
I think the most entertaining one is "I don't like that they use profanity. Maybe you should make up in-universe equivalents like X and Y." which doesn't make any sense to me. If my characters are in 80s America they're gonna speak like 80s Americans, real english swear words and all. The story isn't aimed at kids.
The most common one though? I get "it's edgy" a lot. Honestly though not all edgy stuff is bad? Sure some creators try really hard to get shock value where it doesn't fit, but just including violence in an action story isn't the same thing. Anything "edgy" is there because it suits the story. Stories about angels, demons and death prophecies are gonna be edgy, that's just how it is.