when a coworker asked me why i thought the total cost of ownership for unix was lower than windows i responded like this:

this is something of a religious question but my answer goes something like – unix is an older, more mature operating system than windows and was designed for continuous operation and to serve multiple users. very few tasks outside of tuning kernel parameters require a sys admin to reboot a unix box to affect edit configuration, apply security patches or install/remove software. unix has an extremely rich set of administration tools, scripting languages and even the shell is a programming environment. unix is much more transparent to the administrator via log files, admin tools and when something bad does happen its usually traceable and not just sweet blue screen with matrix graphics.

lastly, people who administer unix systems are generally more technical and have broader expertise (read smarter here) than folks who tweaked a win95 registry setting and then mistakenly thought they were system administrators…