I would put it slightly different: Maintaining windows takes more experience than is generally available to those often given the task of doing so, whereas those charged with administering a Linux (or other Unix-like OS) will generally have the experience of (or inclination to learn) the superficially more difficult skill.

In my experience Windows Server Admininstration is often foisted on some unsuspecting desktop PC support guy, who,lacking in experience on the server platform and when presented with some out of the ordinary problem, will fiddle around in likely looking bits of the Control Panel and Administrative Tools until the thing starts to work. And the people wonder why the server becomes unreliable.

/J\