OS X doesn't suffer from the 'mobilization' of the desktop
That isn't quite true. It is suffering from 'mobilization', and also 'socialization'.
Snow Leopard (10.6) was the best release ever. Since then it has been going steadily backwards, albeit slowly.
I remember reading one of their '200 new features in the next release' that mentioned Facebook 46 times. That was when I knew it was all going to be downhill.
Apple got an early lead in the race to the bottom by taking away great things like expose, but then they seemed to falter a bit.
Linux and especially Microsoft were, as usual, late to the party, but have since caught up with Gnome 3 and Windows 8 respectively.
We'll have to wait and see who manages to get to their 'Hitler' version first.