Windows 10S will be a closed platform?

Fair enough, it was less restrictive, but still unnecessarily Orwellian.

How I imagine I’ll be using UWP:

“Unfortunately this program requires a Win32 device. We hope you enjoyed using up 21GB of your data cap.”
“Mouse and keyboard not detected. Please plug in your Xbox-compatible mouse and keyboard.”
“This app has crashed. Rate, like and subscribe to us on the Microsoft Store!”
“I know I’m supposed to support 49 different screen form factors, but… Please just run this in the emulated windowed mode and stretch it to whatever size you like.”

As far as I can tell, this is just a considerably worse version of Windows RT, more or less. I have a hunch nobody will want it or buy into it.

How is it worse than RT?

It’s better than RT since it gives you a Windows OS performance boost, but it still has the main issue of only running store apps which was the biggest problem of RT

RT was heavily optimised for the platforms it supported (ARM devices), Windows 10 S doesn’t seem to be. there’s the other stuff like locking you into browsers etc through UWP, which wasn’t a problem in Windows RT (which supported Win32 apps via the Store*).

*Win32 app support wasn’t exactly great though.