We should give credit to the early architectural decisions made by Cutler which allow for niceties like the Windows Subsystem for Linux (WSL) that came about recently.
I third the recommendation for "Show Stopper" as well. :-)
i think most - 99.999% - credit here goes to Linus :) Given the modern power of Linux the WSL would have happened anyway - independently of whether early NT architectural decisions help it or preclude it.
For the POSIX, Win32, and OS/2 subsystems that existed at the birth of NT, the kernel capability was all Cutler, and Linux was in no position to contribute.
Showstopers explains the NT kernel personalities.
In particular, I really admire the people who worked on that project, because they had a lot of field-tested reasons for the things they were doing.
But the whole subsystems concept basically cleaved the logical domains in a way that was obviously, even at the time when I read it, not going to extend well in the future. While the POSIX and OS/2 stuff can be seen as a kind of hubristic base-covering (the one kernel to end all kernels), it should not have made the cut in a disciplined engineering organization.