Edit: obligatory explanation (thanks mods for squaring me away)...
What you see via the UI isn't "all that exists". Unlike Reddit, where everything is a black box, there are a lot more eyeballs who can see "under the hood". Any instance admin, proper or rogue, gets a ton of information that users won't normally see. The attached example demonstrates that while users will only see upvote/downvote tallies, admins can see who actually performed those actions.
Edit: To clarify, not just YOUR instance admin gets this info. This is ANY instance admin across the Fediverse.
You are probably seeing two very different vocal minorities, and conflating the two.
Also, there's a very clear difference in expectations between posting/commenting and upvoting. I blame the UI. We naturally expect public actions to be easily visible. The lack of universal accessibilty to the public data makes people unaware that the data is public. Lemmy UIs, including apps, need to make this information (a list of upvoting users) universally publicly accessible before people will change their expectations.
