Those are hot-buttons that have ruined other communities, so whatever the specifics for that sub, my guess is Political Controversy. Anyone on here know anything for sure?
I don't think those are the specific topics that ruined this subreddit. The moderators killed this subreddit: if you express a slightly different opinion than liberal left wing, you will be banned for being "not welcoming and create a bad mood". And you will be banned also to express any polite kind of criticism to all the minorities, except one: the catholics. For them, every insults is accepted.