The cynic in me sees this from the opposite direction. Microsoft has already gone out of it's way to take control of the hardware and kernel (think secure boot

The cynic in me sees this from the opposite direction. Microsoft has already gone out of it's way to take control of the hardware and kernel (think secure boot on intel and the _total_ control on arm). They're now allowing you the privilege of running some posix userland applications (which have no real power) so people don't complain too much when they make it impossible to boot a custom kernel on newer hardware. "What do you mean you can't boot linux? Don't be silly, you're already running ubuntu!"