All you have to do is watch the HN comments on any thread that (even tangentially) mentions women. There's no shortage of of existing programmers / old gamers that are virulently hostile.
I've flagged more posts in this thread than I have at any point on HN, by a lot. It's kind of amazing.
There's some inconsistency with flagging. If the comment is flagged it turns to [flagkilled] at which point it can't attract any more downvotes. But some posts are not bad enough to flag, but very unpopular, and people can just keep downvoting those posts - even after the post can't be edited any more.
It'd be nice if the edit period was as long as the downvote period. And it'd be nice if a [flagkilled] post was still able to be downvoted, or it automatically attracted some downvotes when it dies or somesuch.