HN discussion is only sometimes technical, mostly it's opinion, so the norms should be different. On a site like stackoverflow where the goal isn't discussion

HN discussion is only sometimes technical, mostly it's opinion, so the norms should be different. On a site like stackoverflow where the goal isn't discussion but answers to questions it makes sense to use a combination of mostly upvotes (for good material), lack of any votes (for mediocre material), and very occasional downvotes (for actively bad/outright incorrect answers). In that case it makes sense to engage with the poster and explain the problems, which can increase the potency of the downvote by providing context, while also helping to correct the original poster's misunderstanding. On a site like HN that is mostly just opinion and commentary those patterns don't make sense. Most of the time comments that deserve downvoting are the sort that are either poisonous to productive conversation or just so monumentally wrong they need to go away. In that case engaging with the poster is precisely the wrong course, because doing so usually exacerbates the problem. Either by validating the behavior (if it's trolling) or by dumping a side-discussion into the larger conversation and polluting the SNR.