Kin was just another in a long line of failures by Microsoft in the critical mobile space.
Windows Phone 7 is a hail mary pass, Microsoft will need a miracle or they will be out of the mobile business by 2011. Ballmer should have been forced out as CEO when he handed the market over without even a fight.
Microsoft is correct to fix the developer experience on the phone, the competition has that truly wrong. But developer experience alone cannot combat a huge market share and loyalty advantage.