Two irrelevant niche forums banning you does not make an argument.
Go to /r/conservative and say “I support Biden” and you will be banned within a minute. Does that mean liberals are being brutally silenced by oppressive moderators and therefore we have no choice but to helplessly become radicalised by racists?
They most certainly are. That exact phrase will literally get you banned on some forums. [0][1]
If you want to radicalize people, a good way to start is to marginalize them.
[0]https://www.ravelry.com/content/no-trump
[1]https://forum.rpg.net/index.php?threads/new-ban-do-not-post-...