Another vote for the toaster/fridge hypothesis
“I have great hopes for Windows 9 on mobile and tablets. Just as Windows 7 was "Vista Done Right," it's quite likely that the touchscreen version of Windows 9 will be "Windows 8 Done Right."
The situation is much worse on regular PCs, particularly for knowledge workers doing productivity tasks in the office. This used to be Microsoft's core audience, and it has now thrown the old customer base under the bus by designing an operating system that removes a powerful PC's benefits in order to work better on smaller devices.
The underlying problem is the idea of recycling a single software UI for two very different classes of hardware devices. It would have been much better to have two different designs: one for mobile and tablets, and one for the PC.
I understand why Microsoft likes the marketing message of "One Windows, Everywhere." But this strategy is wrong for users.”