I think I’ve settled on the latter. Disagreement is maybe best communicated by the absence of an upvote? And downvotes work best when they signal something that is just off base, and while not reportable, is not appreciated at a broad cultural level.
Would you like to make an example of a good comment that you disagree with? Because in my world comments that I disagree with are bad comments. If they were good comments I would agree with them. I am not some teacher grading essays and giving points for good structure.