I use the Kinect rather heavily. As I use my XBox One as a media center more than a game system, the Kinect plays a large role in my usage. I like not needing to find a remote control to do anything with my setup.
Also, with Skype I am able to see my grand children, as they have an XBox One as well. The ease of use is such that even my wife, who is not a geek, is able to utilize the system.
Now, could they have sold it as an add-on, or as a bundle option. Yup.