I disagree with the notion that subreddits can be so considered atomically and not part of a whole. r/Fantasy has had this problem where the regulars and the moderators are generally great, but authors they invite to do AMAs will often risk being harassed by users who aren't even regulars of r/Fantasy. The mods even had to go to other subreddits for new beta features condemning some planned stuff specifically because it would enable even more harassment of authors.