Bluebyte suffered financial loss and they did something about it... (snip)...they are the service provider, effectively they took a financial hit and it's well within their rights to undo the damage.
Nobody would have been banned if they did invest the gems to buy as many storehouses as they had brought into the game. Effectively, Bluebyte was seeking financial restitution and everyone who didn't want to go down that road ... well, it's just a game but I don't wanna see what a bank would do if through a software bug you'd be able to withdraw 5x as much money as you had in your account. I bet it wouldn't end with a simple ban of service