If you've ever hung out with a lot of girls (from a guy's perspective), you can beging to understand the trolling community. 1 on 1 with a girl and you can get intellectual conversation, but the minute 3 or 4 girls get together, they start talking about clothes, guys, dramas, and all other stuff that just isn't interesting. I bet girls see it the same with guys too (5 guys together = WoW, DOTA, girls or crude jokes).
Solutions? Keep it small. This fails to keep in line with the existing goals of news.yc (advertising for existing startups, attracting smart people, etc). Another solution? Maybe try to preserve the small community feel as the site gets bigger. One way to do this would be to use user upvotes and downvotes as community boundaries for each user - ie: making their community presence only to those who rate them up, and to make their personal community those who they rate up. This is speculative at best, though.