zlacker

People have differing opinions on downvoting. The majority seems to think that disagreement is enough. Personally, I'm in the same camp as you: a comment has to actively detract from the conversation to get my downvote. I don't see HN changing in that regard though.

Requiring a comment is probably a bit much, but I do think two separate downvote buttons would be helpful to the commenter, even if only they could see this feedback. Maybe one link labeled with "disagree" and one with "low quality" or something. UI-wise this would have the added benefit of letting new users know that HN officially expects them to consider both options.