Necessary for this is that subforums can't have unique names. If a bad mod can squat all the words like "computers", "programming", "coding", newcomers aren't going to know the best subforum is called "RealProgNoBadMod"
You see this in city-focused subreddits. But the reality is the name is power. New users type in their city and join the original one. The hostile mods suppress mention of the new one. It never manages to get critical mass.