I know, the comment is meant to be ironic, actually. I was part of quite a few, and some rather large ones (~100 people). I don't leave communities easily, but if I decide to do it, I do it for good. However, I'd rather stay there and be myself.

What I found is, when you act yourself and if the community is not for you, the community silently ousts you. Then you can just collect your bag and leave. No drama, no fight.

However, most of the time, you can at least affect some of the people and motivate them to be better. Some bad people don't know that they are bad and have their hearts at the right place, so it's worth digging them up and let them improve by supporting them.