It's so very different. Most comment sections don't have peer-moderation. Those that do (e.g. the Guardian) tend to not really penalise comments - in fact, the

It's so very different. Most comment sections don't have peer-moderation. Those that do (e.g. the Guardian) tend to not really penalise comments - in fact, the Guardian doesn't even have a 'downvote' concept. Even genuine rivals to HN (reddit, slashdot) tend to be much less strict on quality of comments. HN will punish you if you write too many comments that don't get strongly upvoted, and it's that kind of approach that helps to guarantee productive commentary.