They're a straight up communist sub. Why wouldn't they? You seem to be complaining that a board game site bans you when you repeatedly post "board games are stupid, you should play video games."
Board games aren't an abstract concept greatly up for debate and they don't influence the minds of thousands of young kids and adults who will and do vote.
Yes, I'll admit to that to some extent, but it's a toxic environment when a subreddit like that regularly appears on the front page yet disallows any sort of significant discussion. For similar toxicity reasons they hid The_Donald from the front page, which I'd say is about equally as toxic. So why's the treatment different here?
Toxic and hate speech are recently invented terms to curtail free speech. If I said anyone who wanted communism were hateful (they hate capitalists) and supporting a historically violent ideology, I'd be as right/wrong as people on the left doing the same.
Anti free speech are a means to an end really, power.
I generally agree with you here actually, I wouldn't want any of this to be used to completely suppress speech, but I don't think it's unreasonable to hide by default communities which are higher friction to some degree.
I can definitely see a completely open alternative viewpoint, but reddit has already gone in a very different direction.