The real question is, after interest in Kinect 1.0 tumbled like a lead balloon, why did Microsoft hold so tightly to the concept? Kinect was a massive success as a fad but what about it made them think it could be the backbone and selling point for an entire generation? I can't believe most third parties told them they were interested in making games for it. If they polled internal developers, I bet they'd get the same answer. As a gaming device, it's not very good.
Even with media and navigation, it's not like Kinect is required. Voice commands could have been integrated cheaply and easily. What, then, is the the real value of the Kinect motion sensing technology being integrated into the Xbox One?
I would love to know what the people in charge of the Xbox One development had to say about it, both pro and con, and what rationale they used in their arguments.