"Disagree" is actually a suggested downvote reason at Ars, with predictable results. Then they published a number of articles that turned out to be perfect bait for flame wars, trolling, and upvote/downvote wars. Comments dripping with twitter-style vitriol and outrage. Engagement up, quality down.
Perhaps they did it on purpose to watch the trash fires burn and the ad impressions roll in, but it really destroyed the comment section SNR and stank the whole place up. I've mostly quit reading Ars except via HN.
It can be frustrating when people use it in lieu of a comment, though. It means that, of all the arguments at their disposal, the person decided to expend only the minimal effort required to produce something that still qualifies as a reply. The communication via binary responses is a great illustration of the decay of modern discourse, if you believe in that sort of thing.
Twitter is a glorified SMS/MMS message
Reddit is a glorified PHPBB forum
HN is glorified usenet.
Specific forums hold specific coversations which the above platforms are the same. HN is targetted towards the tech edge, reddit is targetted towards the average casual indiviual and Twitter/TikTok for the teenages but you still get the same output on all three.
As reddit to HN, The "downvote/upvote" mechanism is old, broken and blatent. Reddit introduced fuzzing to hide the real numbers and as a method to hide abuse. HN had the upper edge of only allowing selected users to downvote after a threshold but that itself feels bias. How many engineers read HN, and how many colleagues know each other with the power to conspire? They all have a problems of their own. HN for example has an problem that if you comment calling on a "fanboy" group, whether it's Elon, Apple, Google in discussion you end up getting lynched for it.
The karma-idealogy has been done and it worked when the internet was growing, however the internet has grown immaturely and we've never shifted away. We still live in an "upvote/downvote" generation where to the point now that folk are paid to farm for internet points. Controversial opinon, but it's civil.
A reason seperates the signal from the noise. The original poster can dispute the downvote given; which Reddit and HN, slashdot are all prone to. Karma points only encouragesusers to vote negative without thought if the output is already negative. As the same with positive.
-- Edit: My current downvote is a good example. I'm at 0.
I have been downvoted. I do not know why. Has some brigade decided to target my post? Downvoted because of my username? Unhappy with the idea? Does someone a personal vendetta agaisn't me?
An explanation to why would provide civil discussion and seperate the bots/power-trippers from those who do want to contrbute civily. The conversation was on point, contributing civily. Nothing unconstructive was within my text, yet it leaves me baffled to why I was downvoted. Was it soley because I clash with someones view and they don't want to challenge it? I like to earn my "internet points" in a solitude fashion but it only takes one bad actor to screw the show.
Forcing the user to give a reason to why, well that would be a different story. Users further down the line could then decide if that downvote was the worth. If that user is a being a bad actor. For now, it's marked as 0 and you can watch the trend.