The downvote is not meant to say "I disagree", it is meant to be used to get rid of spam, trolls or comments not adding to the discussion. If you disagree, respond to the comment with your reasons for disagreeing, like all the quality responses to vectorbunny's comment.
Heck, you might even upvote comments you disagree with if you think they add value to the discussion.
I'd really like to agree with you but unfortunately, pg has previously stated that down voting was OK to express disagreement. http://news.ycombinator.com/item?id=117171
I see that you disagreed with my comment. If you had silently downvoted me (as is "ok" to do), the discussion goes nowhere. Instead you did the noble thing and responded to my comment with an counterpoint.
So, I ask you, which makes for a better HN? One where people downvote to disagree, or where people respond explaining why they disagree?
In my mind it is the latter behavior that makes HN a good place to be.
So regardless of what pg has stated I will continue to believe that it is far better (for HN) to respond to comments I disagree with than to downvote them, for down-voting (aka punishing) someone for saying something I don't agree with doesn't help me, it doesn't help the commenter, it doesn't help HN. So what's the point?
The downvote is not meant to say "I disagree", it is meant to be used to get rid of spam, trolls or comments not adding to the discussion. If you disagree, respond to the comment with your reasons for disagreeing, like all the quality responses to vectorbunny's comment.
Heck, you might even upvote comments you disagree with if you think they add value to the discussion.