Been waiting for years for a commercially viable release of OSX that can run legally on any of the stuff that passes for a PC. Now that would be ideal, nice GUI on top, NetBSD underneath. Looks like I will still be waiting for a while though.
Probably. Apple—like Microsoft—has chosen to favor the desktop over the server, and the two goals are in direct conflict. Apple has written mountains of code to convert a UNIX-like command-line timesharing server into a single-user GUI-based desktop. It has succeeded admirably, but in so doing it has made its OS less and less suitable for use as a server. This isn't really a problem for Apple, which wants to sell desktops, anyway. The only reason Apple chose existing software as a basis for its new OS was that it couldn't afford to write a new OS from scratch (at the time). Writing an entirely new OS, as Microsoft did with NT, costs billions of dollars. Apple might have the cash for that today (no thanks to the Mac, but thanks to the iPod and iPhone), but it didn't back then.
Anyway, GUIs soak up much of the horsepower of any system equipped with them, irrespective of the OS beneath. Glistening, dancing, transparent 3-D GUIs may win beauty contests, but they are very expensive in terms of resources. Unfortunately, today's Windows is stuck with a GUI, which is one of the drawbacks that make it less suitable than UNIX and its ilk as a server. In some cases up to 80% of the processing horsepower of a system can be consumed by the GUI, so just having one on a server is a waste of money. Not only that, but many administrative tasks are much faster to carry out with a command-line interface than they are with a point-and-click GUI interface. Windows is very tiring to use as a server because it is impossible to avoid using the GUI for many tasks.
I'm not sure about the extent to which you can strip the GUI out of Mac OSX, but it's pretty much impossible with Windows today. XP, Vista, 7 … they all come from the NT code base for the most part, but over the years the rock-stable and super-secure NT code base (which is very well written) has been contaminated by imports from Windows 95, which was garbage. The original NT GUI was quite distinct from the kernel, and the system was very secure in consequence. Those days are gone. Both were progressively sacrificed for the sake of users who wanted a more "friendly" and "pretty" interface, which required gutting some of the security features to improve performance (whence DirectX
et al.). I was never happy about that, but that's the way it went. The secure Program Manager and Explorer were discarded in favor of the mess from Windows 9x, destabilizing the system. This improved the "user experience" for Windows on the desktop, but put holes in the security for Windows as a server, and made the system more difficult to lock down. It's still more secure than OSX or Linux, though, by orders of magnitude.
Apple did the same thing with OSX, bolting on vast amounts of extra code to make it pretty and friendly, and thereby undermining the security and suitability of the core OS in a server or locked-down environment. UNIXoid systems aren't really secure to begin with, but adding a GUI makes them worse.
And there are many flavors of Linux that fall into the same trap, only the GUI is more primitive and less functional than that of OSX or Windows (not having billions of dollars' worth of top developers behind it). The fancier the GUI, the less suitable the system is as a server.
Other UNIX systems and clones are also doing this, and I don't know why. FreeBSD is run by a great many people with a GUI, which I suppose makes sense on the desktop (although why anyone would run anyBSD on the desktop is a mystery to me), but I run it strictly as a server, with just a simple command-line interface at the console and a few SSH sessions from my desktop, thereby allowing me to run plenty of stuff on a very small machine.
Anyway, the industry doesn't seem to want to accept that you cannot be all things to all people, and you cannot be the world's best desktop AND the world's best server. Until it faces this reality, you're going to have people running the wrong OS on the wrong systems, and companies encouraging them in their error.