There's already examples of social networks that have upvotes and downvotes public. Besides kbin.social, which isn't the most popular, there are some that have existed for a long time outside of the English speaking world, like meneane.net

Admins and instance owners will be seeing that information, and given how badly some of them behave without any remorse, I don't see any reason why that privilege shouldn't just be made accessible for all. Otherwise you have no way to judge downvotes, which just essentially makes them useless except for current thread sorting.

See who makes it, and you can generally get a sense if they are making a downvote honestly, just circlejerking it, or a high likelihood of an alt because a dead zombie account that hasn't made a comment in forever suddenly decides to downvote in a deeply nested debate. In my experience, there is a high correlation of people who want anonymous downvotes and people who don't want to be called out for their shit, even when they are admins who are constantly peeking to see who's downvoting them.

It's clearly not the doomsday that the naysayers say allowing it will be.