Why are you so hung up on not having the cd in the drive?
I don't know about he guy above but, I own a lot of games, and have a big hard drive. I can have as many as 15 games installed at once.
Wouldn't it be easier if you could just click "go" and the game runs? Instead of fishing out discs, laying them up, not to mention the wear and tear on your drives.
This way is easier and more convenient.