I typically operate under the assumption that basically anything I decide to post on a public forum is not private.
Call me crazy, but I care less about the instance admins being able to see my vote history than regular users. For me the latter will produce a chilling effect on how I operate with the site moreso than the former, even if admins have more power that can be abused. I was already aware of the votes not actually being public and the idea admins could see that info seemed to be a given, but I still think there's a difference between having a motivated malicious user go out of their way to look (making an instance, looking on a different platform, etc) vs making it simple for lay users to see that info within the platform itself (which I what I think is under discussion, currently).
And honestly, if a solution could be determined to help make votes anonymous but still allow admins/mods to deal with bots/trolls, then I'd be all for it.
Because if lay users can see how I vote within the app, then I might start being harassed by people for daring to downvote them or daring to upvote someone. And may stay tracking my voting habits.
In which case, I'd probably stop voting.
Having a barrier to that info is better than no barrier even if it's not impossible, imo.