When you buy something and pay for it, should it be *yours*.
Shouldn't any valuable asset be just that, a valuable asset?
This is going on all over, some companies want you to buy their new products, sometimes for thousands of dollars and if you later on decide you don't want/need it you should destroy it rather than put it on ebay and sell it to someone who does. Barracuda products come to mind.
I for one don't believe in buying anything that has *no resale value*. I insist things I buy have value. I don't buy from any company that tries to interfere with that inherent value.
Every asset should have value. If a company through their policies or through technological means tries to interfere with that inherent value you should avoid buying their worthless stuff. They want you to buy it from them but they later on try to take the value away from you, the solution is to not buy from them!
It's no different in the game industry. If you can't sell it if you don't want it, you should just not buy it in the first place.
The company would then have to change their business policies or go out of business.
If the Xbox 720 is going to prevent your assets from having value, just don't buy it. Maybe rent it, like World of Warcraft.