For years, Microsoft jammed the Start Menu where it didn't belong (Windows CE), now they're stuffing a tablet interface where it doesn't belong.
I'm extremely suspicious of their interpretation of usage statistics. As a "power user" I habitually decline any offer to track my behavior. Also, as discussed in the previous article about Explorer changes, do the statistics speak to the number of people who choose other methods, or to the lack of UI discoverability? Clutter up the desktop of your freshly-bought PC with enough partner icons, and the Start Menu gets lost in a sea of visual information.
The new interface reminds me of the old app-launchers/menus in the pre-Windows days.