It helped that the DOS executable format was the same as the CTOS format - because we had traded Bill Gates our linker (which produces executables) for his BASIC compiler.
Seriously, is it really a victory if you have to adopt the architecture of your sworn enemy?
To quote Linus Torvalds from 1997: "I don't try to be a threat to Microsoft, mainly because I don't really see MS as competition. Especially not Windows - the goals of Linux and Windows are simply so different."
Windows copied futexes from Linux first, anyway.