its not like they destroyed the kinect, its still a major part of xbox.some people simply did nt want the kinect and said they wouldnt buy the xbox with it bundled so MS gave people a choice.
The kinect pretty much destroyed MS» chances of beating Sony this gen.. In the end it's all about profit of course, but if they didn't have that manufacturing cost in the way the Xbone could be on level ground power-wise with the PS4.