People really don't understand just how invasive this is. At that point, if it was programmed to, it could pretend to obey your uninstall directive, while actually overriding your attempts to uninstall the game.
Yep, the other two commenters summed it up well: I'd rather not have software for a game that I play running and phoning home every time I boot my computer (in other words, a rootkit). I also am a Linux user, so they just don't work for me.