it's also interesting that r/socialism , r/anarchism , r/gamerghazi which are respectively socialist , anarchist and anti-gamergate forums are on the top of the list.
Well, from my experience hanging around in leftist subreddits, I can say there's an awful lot of loud and repeated objection to the Reddit admins harboring neo-nazi fora such as the aforementioned /r/european. Whether the admins allowing that speech is virtuous or villainous is a different debate, but the leftist subs routinely criticize Reddit the company for harboring actual Nazis.