I've noticed the exact same thing, it seems like the lack of "voting" system really opens up new people who might be scared to post/comment on reddit because of the "downvote if you disagree" mentality that people have there.
I guess people are just sort of vengeful, because they see something they don't like they wanna ruin a person's day. That's why the whole karma thing wasn't important to me, and part of why I only ever upvoted things I liked, rather than upvoting and downvoting. I just like seeing other people's content, maybe adding a comment here or there, but the vindictiveness of the people there wasn't something I really wanted to INVOLVE myself with, I preferred to just sit back and watch. I like to think of a particular quote, I think it was by Voltaire, "I may not like what you say, but I'll defend to the death your right to say it."