HN doesn't have downvotes on topics/submissions, which IMHO is part of the problem. You can only flag. But there are a lot of stories that don't rise to the level of "this is totally inappropriate/spam", but also aren't very good either.

In any case, I don't get the hate for comment up/downvotes: yes, some people will try to game it, but overall, it tends to get good stuff to the top, and is better than having to wade through comments randomly.