Originated and enabled well before there were other active Lemmy instances or possibly even federation of any sort. It was put in place to stop anti-trans harassment.
Plus AFAIK it’s only truly applicable within Hexbear itself. The main effect it has is that a Hexbear user can’t downvote anything on any instance with their account.
This is a classic example of people not respecting bikes. That’s like saying you’re allowed to make a right turn in front of someone from the left lane as long as you’re just a bit ahead of them.