The ideology of the tech elite is to see themselves as cool, detached, rational observers of the world. So when people feel regular human emotions in response to things, they need some way to deride them for it.
That's a misunderstanding. We're just trying to have an internet forum that doesn't suck in predictable ways. People come to HN for relief from that, in the hope of finding something that's a little more interesting. If they come here and see people yelling the same angry, recycled points over and over again, that's obviously not interesting. It isn't because of emotion per se, and the idea that the people operating this site have any sort of anti-emotional ideology is far off base! I don't identify with that any more than I imagine you do.