At the very least, Steam OS was kind of a far off hedge. Like building a fallout shelter in your back yard. Pretty cheap, kind of spectacular, very low chance of it being used. But, boy, should the need arise you'd be happy to have it.
I don't think that was the original intent, just what it came to be after it was clear that Microsoft wasn't going to aggressively dismantle the open* nature of Windows as a platform. Based on Microsoft's language around the Windows App Store and UWP at the time, and just being Microsoft, that was a reasonable concern.
*That is, open for anyone to develop and release software for without going through a third party.
What a waste of time and energy the Windows Store and UWP are. I've yet to see any apps on there better than the pre-existing standalone ones, and the developer messaging on that front has been all over the road. At various points C++, C#, and JS have been touted as the way to go forward, but from where I sit everybody is still banging on Win32.
The big holdup with UWP, IMO, is that they strictly limit access to the file system. And if you want to give an UWP program access, up comes the age old win32 picker dialog.
If MS really wanted UWP to take off, they should have bundled a UWP file manager on par with explorer, and a matching picker.
As it is, UWP is just another .NET dumped on top of the same old win32/NT base.
From a technology standpoint, no it's not. UWP is very much closer to the Win32 roots than .NET ever was. UWP is COM+ basically, with a thin wrapper.
From a marketing, developer's and practical point of view, I agree with you 100%. They bet so much on UWP, yet their footsteps falter the last mile. UWP is like running an Android emulator on your PC - you have 2 different worlds at once. Really weird and it must confuse "normal" users much more than us who know a lot about both the history and the technology.
