Do people REALLY know how to use computers?
If working at Bestbuy Geeksquad has proven anything -- no, people cannot properly use computers. Regardless of whether or not it's a Mac, FreeBSD, or a Linux box, or whatever, if people don't know how to use the machine, it doesn't matter.
I'd rather have someone working for me who had access to the bare essentials, and was able to communicate with the rest of the company, with a product which broke less frequently because people don't know how to operate the machine in the first place.
Sure, Unix based OS-makers are producers of rope -- and you can definitely hang yourself much easier with Unix, if you do the right thing. The catch is that with Unix you're stuck with a smaller sandbox, so the likelihood of fubar'ing a machine is much lower, and it's much simpler to script common actions to make sure the machine is secure and up to date.