I don’t disagree that they’re ineffective, but the closest thing to a cohesive argument that people have raised above, is that they stifle World PVP.
Which… well… that was kinda half the point of them, so they were effective in some ways. Just not targetted enough.
But yeah, they were in Vanilla at 1.12 in 2006, Blizzard already said so, and no-one has given a compelling reason why they need to be removed.