Frankly, as someone who's been a moderator of a cosplay group, kicking someone out was a rare thing, and it was typically for things like pedophilia or repeated harassment of someone in the group (ie. a girl was being legitimately racist to a Filipino girl and saying she shouldn't cosplay characters that didn't match her skintone repeatedly, bugging her even after we asked her not to talk to the girl again. It was a suspension from the group technically, but she treated it like a ban and hasn't come back since.)
Nevertheless, we only ever had to kick out one moderator for being a pedo, one member for being a pedo, and the racist I mentioned above.