I think this is a way that fandom can be crazy-making, because it has fairly predictable patterns (white boyz rule, basically) and if you're not in that majority you start doubting your own perceptions (maybe Kylo Ren is the protagonist and hero of Star Wars?). This, in turn, pushes out people who don't agree with the majority because it's no longer fun. Sometimes they may be converted, especially if their positions were "soft" in the first place. Either way the groupthink becomes stronger and more entrenched.