It should of created a $99 ad-on, that would allow the Xbox One to play 360 games. Essentially, all it would be is an Xbox 360 processing core, which would use the already available hard drive, controllers, I/O, and Kinect 2.
I'd wager it'd sell like hot cakes, and be profitable. Because the entire Xbox 360 is now what $150-$200? Minus case, controllers, hard drive, all output components, they should of been able to pull it off.