While it may be a little demoralizing to see a downvote on something you care about, 'tis a part of life. When I see something I posted get downvoted, my first instinct isn't to assume it's people being malicious. I take it as an oppurtunity to look at the post and ask myself "what is it about this post that people don't like?".

I noticed another person brought up the YouTube Dislike removal thing, and I'd like to add that programmers were rightfully upset to the point of creating a third-party API and browser plugin just to bring it back. That was more in response to the rampant amount of misinformation and scam videos on the platform, but I think it has some resonance here as well. I don't think taking away a feedback mechanism, regardless of it's potential for abuse/harassment, is a good idea.

If I may, I'd like to bring in another comparison- E621. Say what you may about E6, but the up/downvote system there works well because some posts just aren't good. Sure, it may have passed the janitors, but the post itself and/or it's contents may be objectionable. With E621, you can hide posts that pass a certain score threshold. This is a good way filter out some of the more... questionable things for a lot of users on top of the existing blocklist system they have in place. Some people may try to game the score system to artificially boost or dump a posts's score, but the admins/moderators are pretty good at nipping that in bud, so to speak.

Finally, I'd like to bring in the (#)fediblock argument. Even if an instance blocks another, it doesn't stop the offending instance from replying/reacting to posts that it may have discovered through a relay or another instance. All it does is stop the defending instance from seeing the reply/reaction. Disabling downvotes is the same thing. You can just hop to another instance and see if your post was downvoted.

For now, until the lemmyverse becomes a bit more stable, I don't think messing with any core functionality is a good idea. It is definitely something worth revisiting again at some point. Who knows? Maybe the developers are working on something to address these concerns.