/r/history has a similar policy on holocaust denial. On paper yes you should not block certain topics from being discussed but in reality they were being bombarded by obvious nazis and trolls and other bad faith actors who were purposely trying to pollute the discourse. There’s an intentional goal when you call certain details of the holocaust into question where you get people to eventually question whether it happened at all, and whether there is in fact some kind of Jewish conspiracy to make themselves appear as being more victimized than they are.

There’s enough concrete evidence that the holocaust did indeed happen, that it is no longer up for debate