Downvotes suck. I get it, they are made up internet points coming from strangers (or bots) that you know nothing about, and you shouldn't let that get you down. Still, putting in a few minutes of effort to share your opinion and engage with the community just to see a downvote is disheartening.

Based on the patterns of downvotes I see on a post, it seems like there is usually one or two people downvoting everything they wouldn't personally say themselves. Extrapolating from this, I presume there is a population of users that contribute more downvotes than anything.

Personally, I don't think the platform should allow any user to spend more time tearing things down than building other things up. Only allowing downvotes after so many upvotes would help stop trolls and could help generate more engagement via upvotes.

Edit:

The upvote/downvote count would be a global count including posts and comments, not a post specific count. This solution does not prevent downvoting, it merely adds friction to those who predominantly leave negative feedback by ensuring their positive feedback elsewhere. Sure, some would go on to upvote unsavory things, but others would attempt to further engage with their interests, and some would simply lurk.

If any good faith user approached the limitation, they would likely be better served by curating their feed.