Personally I don't care about downvotes. If you don't be yourself on an anonymous platform, how can you be yourself in real life? Plus this makes all posts conform within the general trend rather than creating discussions and meaningful debates.
I think downvotes are important to social media. Without them, trolls have a much easier time rising to the top, as they get lots of upvotes but no downvotes to balance it out. This is why the most-followed content on sites that don't have downvotes like "Twitter" is some political bullshit. So yeah, I think downvotes are crucial.
Downvotes are critical, in my opinion, especially for recommendation posts. It’s a good way to combat astroturfing and let genuine discussion rise to the top.
Downvotes give you additional information. This can be:
OP is posting crap that the mods haven't spotted
OP is just plain wrong.
They could be intentionally or unintentionally spreading misinformation. Lies should be squashed. (Although, I believe people who unintentionally spreading misinformation should be given an opportunity to correct themselves. Which can happen in replies.)
There is community disagreement with OP
I try not to use downvotes like this. But some people do, and it should be noted.
OP's position is controversial, i.e. upvotes and downvotes are split around 50:50.
One consequence of removing downvotes is crap can appear to have more support because it can rise above the mediocre. I'd rather see the mediocre than the crap.
In all these cases it does require reading in-between the lines to figure out what is going on, but again I'd rather have the downvote signal than not have it.
Removing downvotes does not improve the experience other than giving the illusion that nobody disagrees with anyone else. Unless your instance has some very weird need to maintain a false sense of positivity, downvotes should be enabled.
In the beginning on Reddit at least it felt like the votes worked as a validation of the argument. But as the site grew it was impossible to convince people, that even if you disagree, a comment can be valid and worth your upvote.
And when enough people give up and downvotes based on whether they agree or not, you basically get an echo chamber of popular opinions.
I have my own little rule. If I make a comment I have to upvote the post or comment that I’m replying to, since it somehow gave me reason to spend time thinking about and commenting on.