What if you want to play a game but don't agree with the price for it?
What if you don't like a developer/publisher and that you don't want to support their business model?
What if you bought into the hype of a game and it was complete utter bore/crap and you want to be compensated for part of the $60+ you were ripped off for.
But don't worry, I will be "out of the game" when you young kids accept the gaming overlords digital distribution model and it become the only option to purchase media.