Moderators can't see everything and HN doesn't operate under some 'no negative comments, ever, at all' ruleset. It's one thing to point out, in some detail, tha

Moderators can't see everything and HN doesn't operate under some 'no negative comments, ever, at all' ruleset. It's one thing to point out, in some detail, that the argument in a particular article is very poor, it's a completely different thing to directly attack another user. Just like anyone is free to write clownish, provocative invective on their blog, people can point out its nature when it pops up on HN - especially when the main reason it does is its clownish provocativeness in the first place. You could always flag and/or email the moderators if you think something needs a further look, though.