Anonymity has a large role to play, and shapes a lot of people's actions and decisions. The smaller the group (ie. a split, general, etc) the more of an identity you have, despite being a completely anonymous image board. Your typing habits, hours of activity, etc all lend themselves towards and shape that identity. Whereas in faster moving boards and one-off threads, you can easily just get "lost in the crowd". No one has the time or patience to remember a seemingly random passerby's traits, because there's the assumption that you will most likely never see them again.
There's no such thing as true anonymity if you want to participate in a general, split, etc. You should always assume that in smaller communities, even without solid identities, that people can/will recognize you. I've self-doxxed multiple times since /hlgg/ was formed on /jp/ (no I'm not Joseph), but there's no sense in going salted-earth and nuking my identity elsewhere, because I post and act the same regardless of whether I'm here or in a holo's chat.
I also think a lot of pot-stirrers would act differently if they assumed that their oshi saw them posting here and could recognize their face in the crowd, so to speak. She would not be proud or think it's funny that they're wasting their time and energy making fun of her friends and coworkers.