You don’t like what I say, how will I know why? You downvote because others are downvoting or you are too lazy to come up with a counter argument.
So I propose, if you downvote, then HN should open up a text box asking you to justify. So people will know if it make’s sense. If others downvote that, they should justify that too. So downvote and justify all the way.
Make it so tedious, nobody downvotes.
Downvotes are a useful tool. If you can only ever upvote something, that is when the site-value is vulnerable to brigading - HN is probably not interested in lowering the signal-to-noise if farming accounts to upvote (and only upvote) is an option.
Also, a lot of downvoting on the internet is just "I disagree with you", or "I don't like what you're saying". It can be personal, and not necessarily useful to the original poster.
In other words, I disagree with you. Though I won't downvote (flag, I guess on posts) you. This time :)
[aside: I'm not some apologist for HN. I'd love to post my own pet-project [1] but I've linked to it too often in posts where I though it was relevant, and now HN won't accept any post with that URL. Caught by my own ignorance and actions, but it's still their right to run their site as they see fit]
1: (I'm assuming that HN-links are ok :) https://news.ycombinator.com/item?id=50151036#50151160
catchnear4321•20m ago
Shouting “brigading” doesn’t do much to change that.
It also ignores the impact of upvotes, which can be used to the same effect, yet doesn’t receive the same request.