That's why I'm here, kind of. I personally haven't got into any pointless arguments with SJWs or anything like that, but I have got too aware of Reddit's flaws.
Not just once, I have written a comment, but not posted it, because rereading I thought to myself: "I can't post that, there are crazy people here and it's possible to find my real name.". I'm not even talking about posting controversial, to the specific subreddit, comments, which itself is a flaw with Reddit. I'm talking about subreddits without any obvious ideological alignment. Neither I'm saying shitty things, I always thought, that you should post the way, that you wouldn't be embarrassed to read it to your mother.
Then there's the problem with moderators. Feels like too many of them are corrupt and too many aren't acting in the community's best interests, intentionally and unintentionally. The motives vary (ideological, monetary, power hunger), but the result is the same - very controlled communities with hidden agendas. It's not a noticeable problem for the average user and there are plenty of honest, small/narrow subreddits, but it makes me feel uncomfortable and unwilling to contribute to anything to Reddit. Self-appointed moderators are a bad idea.