I wouldn't be surprised if they are doing this more to stop second hand game sales and game CD sharing/exchanging than the root key attack.
For example, when I was at college when the PS1 was still going strong, students regularly exchanged games with each other. However, if the game is locked down, this this will kill off this type of game swapping. Also, I'm sure this would kill off second hand games, since there is no way to tell for certain how many activations a used game has gone through and you could end up buying a used game that cannot be activated.
Yet another highlight of DRM going out of hand.