Honestly the most baffling thing I found about reactions is that they're all public information. I don't just mean the reaction score on a post, that's normal these days. I mean how you can go into your profile history (or someone else's profile) and see exactly who reacted to each post, which is something most sites don't allow for non-moderators. I'm not sure why this feature exists, especially given all the pro-privacy stuff coming out of the EU. I guess in the optimistic case you could see who disagreed with you and have a civil discussion? In reality it just leads to users X-brigading users they don't like or calling their vote out publicly in the topic (which is about as effective as someone whining about downvotes).
Personally I find that helpful because I know there are posters that agree with me a lot on some topics, and posters that reliably disagree, but if someone who usually agrees with me disagrees (or the reverse!), or someone gives some posts in a thread agrees/likes and others disagrees, I give more attention to that feedback.
I do agree it's tedious when people do the "Tell me why you disagree with me, (user), you Internet Coward!" shtick. But I don't see that as a MAJOR problem, and I don't really agree it's necessarily an issue to see who's reacting to your posts. Why should your opinion be more anonymised than your replies?