> What actually happened [re Windows RT, but I think the point applies to UWP in general] was that the users went WTF because none of their native apps - which, contrary to his take, were very much alive and kicking! - worked there, and devs went WTF because they were told that they'd need to rewrite everything yet again in some new thing that was kinda sorta but not quite like WPF, because Windows just hated .NET that much and couldn't accept that the devs liked it over their stuff. So the app store was a barren waste, and without apps there would be no users.

The fact that UWP XAML was its own new thing and not a extension of an existing Microsoft GUI app framework like WPF was not necessarily a "we hate managed code" thing, or even a "we hate those guys who invented managed code and want to screw them because we're Windows" thing. After all, .NET managed code had equal access to UWP through the .NET WinRT projection!

And to me at least (I didn't work on UI-facing stuff in Win8), it was absolutely conceivable that UWP could have just delivered Windows Phone 7 Silverlight's version of XAML to native code apps, with a thin adaptation layer to let even unmodified WP7 app binaries run on the desktop Windows .NET Framework with the WinRT projection and to allow slightly modified WP7 apps to look good in landscape mode on both Windows 8 and WP8. If we had done that instead of making UWP XAML its own thing, and if we had integrated the Windows Store with the Windows Phone Marketplace from the beginning so that Windows and Windows Phone apps could be sold as variants of each other through a single Store/Marketplace product entry on Windows 8 GA day, then I think we could have brought a lot of people forward who were already making good WP7 apps, and the Store wouldn't have been so empty.

Furthermore, IIRC much of the original UWP XAML implementation was done by the original people who built WPF and Silverlight the first time, and they would have known what they were doing in separating UWP XAML from Phone Silverlight. That they didn't go in the direction of extending Phone Silverlight was not necessarily shortsightedness on the part of provincial Windows people. Maybe they thought Phone Silverlight actually demonstrated fundamental limitations of WPF or Silverlight XAML or the Silverlight "coreCLR", or they wanted to make breaking changes as lessons learned from Phone Silverlight, which was put together about as hurriedly. (Windows Mobile 6 -> Windows Phone 7 first previews = 1.5 years; Windows 7 -> Windows 8 first previews = 1.5-2 years, tending toward 1.5 years if you account for the frantic re-planning after iPad came out in early 2010.)