That's not just your opinion, that's surely exactly the intention of the downvote option. If I were to suggest one small change to HN it would be to have to select your reason for downvoting (or flagging), such that "I disagree" is clearly not one of the available options.
People would still tend to (ab)use the downvote button as an outlet to express their discontent / disagreement. Just human nature, we can't all be robots.
To be clear: I frequently find myself undoing my downvote actions after a moment of reflection, in cases where I realize I've done an impulsive downvote because I didn't "like" the comment. I'm not perfect (first to admit: far from it), but I do try to be a good member of and positive force in our community.
Really appreciate you folks, most of the time this is a really cool place to spend time. Also, @dang deserves a lot of credit for keeping things headed in the right direction.
...that's surely exactly the intention of the downvote option.
Someone will be along shortly with link to Paul Graham writing that a downvote button can be used for disagreement. I disagree, so I don't have that one in my bookmarks, sorry.
It's not just Graham; it's current site moderation policy, and the rationale has been explained repeatedly (to wit: we don't want meta-discussions about the validity of votes, which are boring and outcompete substantive conversations, since everyone can come up with an opinion about a vote on the fly).
I knew the policy about meta discussion, but on a thread that itself was meta, talking about the thing using the thing, I figured I'd lay out one comment about commenting. I discovered, on closer inspection, that the guidelines also ask one not leave comments about the why of flagging a story. I rarely flag stories and have been guilty once of doing just that.