This is hardly surprising. Not to crap on MS, but I do think Linux has traditionally just been a better operating system for servers, probably due to the fact that that's where most of the funding for Linux ends up going, with the desktop versions of Linux being sort of secondary. It doesn't help that a lot of serverey software is kind of designed with POSIX-ey stuff in mind. Node.js took awhile to get Windows suppor…
But for servers, I much prefer Linux. It uses less resources, and it's so much easier to get it into a known and consistent state that Windows.
Also, something about having a GUI for servers has always felt... wrong somehow!