[nocman]

Well, those kind of comments do get downvoted, but people on HN do also downvote comments simply because they disagree with them (often regardless of whether the comments are perfectly civil, and just express a point of view that the downvoter doesn't share). Of course, many of those downvoting these comments would be quick to label them as "misguided" or "unhelpful", at which point there is usually little reason to argue about it.

It's an imperfect system, but I'd guess it is a net positive at least most of the time. It does help to filter out when people are just being total jerks.