So...you're lamenting the fact that something wasn't taken away from the consumer? The reason Steam is successful isn't because they block used game sales, it's because they have proper game sales.
If Microsoft wants to join the digital future, they need to price the games competitively like Steam does. It really has nothing to do with allowing used game sales or not. If people can buy a relatively new game from Xbox Live for 5-10 bucks they will drop discs like a bad habit.