Well, exactly the same can and is happening on specific Lemmy servers too.
One of the vegan instances bans you if you downvote anything that speaks in favour of veganism. Not that I just do this out of spite, but there was this time where a thread about vegan cat food gained traction and I downvoted some comments that were really borderline. Ban within an hour.
Same on that notorious star trek instance. Go ahead and put some downvotes on Discovery related posts, it will also earn you a temporary ban.
So let’s not pretend that it’s only big bad reddit doing this.
I feel like there’s a difference between various moderators power-tripping on their own little fiefdoms, and a site wide policy.
Just keep in mind: your upvotes on Lemmy are visible to anybody who runs a Lemmy instance.
God help us if Elon Musk figures out how to run one.
ETA: I mention this because the current government wants to find anyone who does this.
The [unelected president] moaned on his platform that some Reddit users on the subreddit r/WhitePeopleTwitter had broken the law after they allegedly revealed the identities of his so-called DOGE goon squad.
Or just open the thread on an mbin instance. Here’s everyone that upvoted this thread.
Edit: Downvotes (reduces) are less exposed, but as you said, someone can just run a fedi instance that exposes them to everyone.
I think all reactions should be exposed.