when you consistently generate such effects, you become responsible, regardless of what's wrong with others or their views
Sure, some of yummyfajtias comments are a bit trollish but he points out real contradictions in submissions and other comments. I have his threads bookmarked and visit them directly to check my thinking. It would be a huge loss for HN.
It's like the Socrates thing all over again. You would be banning someone offering interesting insight for upsetting the social order of the place.