I think you nailed it. It's the hyperbole. The inability for people to even try and see the other side of a discussion.

You know the core thing I think that really breaks reddit, and it's not obvious, but good comments get squelched all the time by being downvoted, because they are unpopular opinions. Not that they are not well thought out or not well argued, but simply because a bunch of people see it, downvote it and it ends up being buried.

It kind of discourages people from posting dissenting opinions and having a real discussion, because whats the point of posting something you know will probably get downvoted into oblivion?

Come of think of it, I've sat in front of my computer, and spent an hour composing a long, (what I think was, haha) thoughtful and well-written reply, only to just close the tab in disgust because I know that my opinion wouldn't well received and I'd have 30 comments of people telling me to go fuck myself, and find my comment buried and hidden.

The whole upvote/downvote system polarizes the discussions, bit by bit, which polarizes the community. Add that to a management that isn't transparent at all and you end up with a site that has effectively bred into it's community it's own problems.

Ew.