I agree on the Power Management issue and long term UWP is the path forward. Of course everyone still wants their Win32 apps now which was my understanding why the lack of availability of Desktop Apps lead to the RT demise. so in a way we agree the Desktop led to the RT demise just not how or why it happened.
The puzzling piece to me is Windows NT débuted on Intel, Mips, and Alpha processors had stints with Itanium, & PowerPC so I don't quite get the manpower for Office on RT unless it was to create/recreate the Win32 APIs for ARM... which perhaps weren't initially planned but it would have bee the same type of effort required for MIPS, Alpha, Itanium, & PowerPC. Yeah, it's been some years since so skills may have escaped. Architecturally the HAL was supposed to make Windows portable across different chip architectures without massive development of custom code to port the OS. Unless it was a complete hack job and wasn't done according to Hoyle although IIRC devs could side-load Apps onto the desktop which implies to me the Win32 API was there. Something doesn't add up.
Regardless, it seems MS wants to try and force the issue with moving to UWP and has paid a price for it which may be still mounting. It's a tough position because I also believe that Win32 apps on a 6" screen makes absolutely no sense. There might be a very few that are usable the rest would just be ridiculous unless you're attached to a larger screen.
So we have a quandary; what to do (will be done) with Surface non-Pro and what to do (will be done)with Surface Phone? I'll leave that for everyone to contemplate.