Can't get rid of them because they're used for banning. The game remembers who's banned by their BLID which can't be changed, whereas name can be.
And it's a nuisance to ban by ip because there are players who have siblings who play and you may want to ban one person and not another.
They're toggled off by default, but you can't blame people for turning them on.
I know people who I only know by their BLID because they change their name so much.
And no, discrimination based on BLID should not happen. Ban users who do discriminate and don't visit the servers of admins who discriminate. That's your only solution.