Yes... and why are people using those "countless single-purpose archaic unix servers"? Because Microsoft perpetuated this archaic model in the 1980's and 1990's when it decided to follow that model with NT, rather than any of the more modern approaches.
What more modern approaches? The only other "modern" systems I can think of from the beginning of the NT era are Amiga and eventually BeOS. Can you detail a more modern approach to a desktop system? Unix is still a couple decades behind NT in architecture.
Microsoft's lack of vision and innovation in the 1980's and 1990's is responsible for why we still program in C/C++ and use UNIX-like kernels.
Can you name a better language for writing kernels? C is basically the optimal language for writing system code. You haven't presented a revolutionary alternative yet.
It took Sun and the Java community to drive managed languages, garbage collection, and virtual machines into industry and server applications. It took Microsoft a decade to catch on to that one.
Virualization is big because UNIX is too awkward to work as a multi-role server, so you use virtualized myopic UNIX servers to replace what could otherwise be done by Java EE or .NET.
"Comparable" only in the sense that both of them are obsolete junk. But since I have to choose one or the other, I prefer the cheaper, simpler, open source junk.
One system is designed and has a unified vision and architecture, the other is a haphazard collection of incomplete and inconsistent subsystems written largely by amateurs. The difference between them is drastic. If you can't grasp this, then your requirements from your systems must be very superficial.
Anybody whose time is valuable would be a fool to run Windows: any serious computing on Windows is a bottomless time sink. On standard hardware, Linux just works.
I have never owned a system where Linux "just works". Most users purchase computers with licensed and customized operating system images. Replacing these with a hacked together 1970's operating system designed to work over dumb terminals is simply beyond retarded-- Linux on the desktop is a non-starter. Its marketshare reflects this.