To be fair, /r/programming is probably one of the most toxic subreddits itself.
I've never found another subreddit where everyone is as unbearably angry and negative. Too many programmers suffer from social issues for a laissez faire community to be a fun place to frequent.
With the exception of /r/fatpeoplehate, those aren't the subreddits I think of when I think of hateful subreddits, as they are mainly low-subscriber fringe groups. The same sentiment that FPH had lives on in other "angry" subreddits that reach mass appeal (like /r/justneckbeardthings, and much of /r/blackpeopletwitter).
I think a sentiment analysis of posts from the major subreddits would be an interesting read.
I've never found another subreddit where everyone is as unbearably angry and negative. Too many programmers suffer from social issues for a laissez faire community to be a fun place to frequent.