Let me fix a couple of things for your
Microsoft in 2015: Mobile disasters, Windows 10 and shows heads in their clouds arses
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The problem with Windows 10 and the UWP app strategy is that most mobile devices run iOS or Android
No the problem with Windows 10 is nobody wants it. The only reason I installed it on my mother's new computer is that she won't keep her fingers off the download button when the notices pop up, so it was better to put it on up front instead of answering the frantic call when it stopped working.