HN comments are not thinking, doing anything, or building something. It is a place where you gain attention and karma not from some constructive act. People post constructive things, then commenters vie for attention. If you look at threads, the top "comment" on them is something about a completely different topic. And then they mostly go downhill.

Hacker News is a good source for interesting posts and idea. The comments are mostly worthwhile for watching how a social machine produces very weird stuff. It is not the people who are contrarians, it a function of the machine.

Zeynep Tufekci talked about how twitter affords outrage and the Arab Spring, but did not afford a way to do anything constructive with that outrage. (Twitter and Tear Gas, available as a pdf). HN commenting system affords .... what you see here.