Ultimately, I don't think Microsoft's failure in smartphones has anything to do with consumer vs. enterprise. I knew the Windows CE/Windows Mobile folks and they got consumers. The real problem is that back then (and maybe still today) marketing ran Microsoft and the mantra was preserve the Windows brand at all costs. The Microsoft phone UI must be the same as the Windows desktop UI because that was the way Windows remained relevant.

I think the Modern UI (the UI formerly known as Metro) is clear evidence of this thinking. When Windows Phone and its new UI first was released, and had modest success, Microsoft was faced with the old issue of maintaining Window's relevance.

Finally, having come to the decision that the old Windows UI doesn't work on small screens, Microsoft did the only thing they could do and that was to change the Windows desktop UI to match the Windows Phone UI so that they could still call it Windows and keep it relevant.

The difference at Apple is that they are not about preserving crown jewels, they just build great products and if iOS ends up relegating OS X to the discount bin, so be it. Microsoft could never, ever, allow Windows to go to the discount bin. If Windows fails, Microsoft fails because they were one and the same.

Had Microsoft, back in the late 90s, not let marketers drive their strategy and accepted the fact that they could, in fact should, have different user interfaces for different device types, and further accepted that if that means Windows some day goes away, they may have stayed in the race rather than falling so far back that they could never catch up.