If I didn't know better, I'd interpret MS's actions as trying to drive desktop computer users to Mac and Linux; kind of like their redesign of Office (ribbon) driving people to Google Apps.

MS doesn't seem to be "protecting" it's market share anymore; it seems to want be seen as an innovator, rather than make its current users happy (which seems a very odd philosophy for a company with 90% market share).

The only way I can understand this is to believe that MS is consciously "ignoring" internal usability data in order to push forward an innovation agenda.