so microsoft’s strategy has been, ‘one OS for ALL devices’

Apple’s strategy is, ‘one, seamless, continuous experience across ALL devices’.

It might sound like a subtle difference at first glance, but it’s a universe of a difference.  Microsoft demands the user make the same OS work no matter what device you’re on, so we find folks griping about a touch interface on a non-touchscreen device etc.

The Apple user might start writing an email on his/her iPhone, then sit down at a computer and finish it there – the half composed email is magically there.  The UX fits the device, and there is continuity of the task itself.