If Windows was Unix based, it wouldn't mean there'd be Linux drivers out of nowhere. Drivers are per kernel - Linux drivers are different from FreeBSD drivers, even though they're both Unix.
And NT is like, part VMS, part DOS (for compatibility), and part-some unknown stuff.
To correct a small error by Jimmy - they weren't going to port NT to VMS, that's an OS. You meant port it to VAX or Alpha. Which kinda-sorta happened with NT 3.1, but not much after.