@Just Enough
"Windows" is a long established, recognised brand that sells.
That's clearly what Microsoft's marketing department thought.
Having a phone/tablet that is "the same as Windows" on their computer is a good thing in their eyes, because they don't have to learn another OS to use it. Users like familiar
And that's exactly why they thought it.
What they didn't get as far as working out was that it's not actually possible to square that particular circle. Of course everyone wants Windows on their phone to be the same as Windows on their desktop, that means less effort. But then if they get that, everyone actually hates it because Desktop Windows doesn't work on a phone, and Phone Windows doesn't work on a desktop.
Faced with contradictory goals (Everything should be the same across all products <> Users hate it when we try and use the same UI on multiple products) they went into a flat spin and started changing things apparently at random, mostly not for the better, trying to work out what to do.
If they'd thought a little harder they'd have realized that what this all really comes down to is that what people want is to get as little hassle as possible, and if WinPho had delivered better in that respect by just doing everything you wanted it to with the least amount of fuss and never doing anything obviously weird, then no one would have actually given a damn if it was the same as desktop Windows or not.