Agreed, though personally I think that the complement is also true, and maybe more insidious: A lot of comments get upvoted because they state an uncontroversia

Agreed, though personally I think that the complement is also true, and maybe more insidious: A lot of comments get upvoted because they state an uncontroversial, obvious position that everybody agrees with already. This is insidious because it encourages people to be the first to say the least interesting thing in order to get rewarded with comment karma. Those comments bubble up to the top of the thread, where they're held aloft by more and more people who see their existing opinions restated. Ultimately the reward structure encourages discussions where people are indulged, in the same way the punishment structure discourages people being challenged. I'd say this effect is more pronounced on Reddit than HN, but you can see it here too. I'm not looking for "edgy" comments, I'm just saying that it's more useful in the long run to upvote comments that provide new information or perspectives, or at least state a common sense position in a different, compelling way.