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.
The problem is that there’s no way to enforce this in practice. All of these conversations about voting culture, with examples and pontificating always just come off as “everyone who drives slower than me is a grandpa, everyone who drives faster than me is a lunatic.”