Someone else commented what I also suspected. It is not that MS didn't do any usability studies or analysis what is better. It is just that they suits had a pre established vision on how to do things and then they tossed the studies that didn't support that vision and kept the ones that did.

It is like wanting a nice feedback about Star Trek, so you go to a Star Trek convention and stay the hell away from any Star Wars Convention. There, you will have massive data that support your pre established notion that Trek is the best thing since sliced bread.