I would argue that the belief of communism is besides the point here - even if certain people really truly did know better than certain other people, about whatever matter, then that is all the more reason to be particularly convincing with sound argumentation espousing rational behavior, rather than trolling and brigading and banning tactics. And if not... then they may feel as free as they like to complain, as people who refuse to do otherwise go ahead and block them, and warn others about what they are likely to encounter if they go into those echo chambers.