Buried in a very misleading article is a good point:
> (Apple) did not rewrite the OS X desktop that runs on Macs, nor did it try to re-imagine the desktop computing paradigm. Apple created something entirely new that was always designed with touch screens in mind.
I have never understood why traditional desktops must adopt to touch screen based GUIs. Why can't both be independently developed? Why is Microsoft and Canonical trying to unify seemingly unrelated user input paradigms?
Because they both have an existing desktop product, both of which are dominant in their own sphere (Microsoft: desktop computers, Canonical: Linux desktop computers), and they'd really like to leverage that advantage to get into the touch-based market, which is predicted to grow massively while desktop is stagnating.
I guess there are also a few products where both input paradigms make sense, ie. the tablet/notebook hybrids, you wouldn't want to entirely different user experiences on a single device depending on the currently chosen input, so you make a hybrid user experience fitting the hybrid device. The other choice would be simply not supporting hybrid devices, but clearly that is not what Microsoft has chosen to do.