"are POSIX-compliant"
The POSIX subsystem of Windows was a very limited one, mostly available for commercial reasons only, and it needed Software Services for Unix to get a decent source code compatibility.
Now Windows 10 has Linux running on top the Windows APIs, not viceversa. The kernel are quite different.
And again I warn about the risks of having a single codebase for everything. A big bug could become really catastrophic and put at risk any system.
True evolution need competition and diversity.
Biting the hand that feeds IT
