> What would you do in real-life? Would you make a mockery of them? Or would you simply ignore them?
I guess it depends on the context right? I remember in college there used to be these religious fanatics that would loudly berate strangers in the plaza; whenever someone would walk up and try to "debate" them, it would just make things worse, but sometimes someone would just say something really funny and the mood of the whole crowd would change and the extremely aggressive obnoxious fanatic would end up packing it in early or going for a new tactic. (Maybe not immediately, but it did seem to have an impact overall)
My point isn't like, go pick on people, that would suck, I'm just saying that humor is a really useful tool sometimes. Self-serious "be nice" policies can remove those tools and give some unreasonable people a nice cloud of cover to haunt places.
Maybe a different metaphor is better. A good community is like a garden. Nobody likes pesticide, but sometimes if you have a pest problem... It's all a judgement call right. "Be nice" policies only work if you can assume the other people you're interacting with are reasonable, and that's not really always true.