Bots and Cheaters.

[LianaThorne]

I don't know why they don't just do a check if the bots are under the map and ban based on that. Plenty of other games ban people who go OOB on the map and there's no real reason to go OOB under the aetheryte unless you want to advertise RMT in say chat.

Then they'd have to patch up all of the holes above ground that lead under the map or people who stumble upon those will get hit as well.