Fast user switching would still mean having to log-off/out and then having to log in again. Plus, if the game was left running in the other account, wouldn't most of the game files be locked if they were still in use, or not kept in sync if your game only updates high score files and such-like when the game is exited, with one overwriting the updates of the other.
It's far, far simpler just to allow a user to switch a profile within the game itself. Every other game does this. Also, not everyone may have an account on the PC it's being played on, e.g. having friends round, etc.
It's far, far simpler just to allow a user to switch a profile within the game itself. Every other game does this. Also, not everyone may have an account on the PC it's being played on, e.g. having friends round, etc.