I'm the Client Architect for a Fortune 60 company (that should help narrow it down (g)) and have been doing this for this company for 18 years and in the business of microcomputers since the "over the counter" start in 1977, so I think that qualifies me to discuss this. I am responsible for 35,000 plus Wintel PCs and around 2,000 Macs. The Macs are fine for what they can do but most of what we do has to be mainstream, off the shelf and 100% compatible with our customers or suppliers. End of argument. Macs aren't. You can build anything you need to run on a Mac, but you can't buy it off the shelf the same way you can in the PC world. We don't build, we buy. It costs too much to custom code everything we need.
Oh, and the argument that Macs never crash. Bull. And when they crash, forget it. When Macs crash it's ugly, and not reasonably recoverable. We use "disposable PCs" in our shops. We can have a PC hit by a dump truck or a meteor and have our users (that follow our rules) back up inside of a half hour. Every Mac is a custom installation and requires days to restore.
Macs require less IT staff because Macs can do less. So if you're satisfied with doing less you need less IT staff. Ipso facto. And I don't play games on my company PCs (I might surf to FR, but I can defend that... really (g))
Setting aside the question of which platform is better, I'm not so sure that it's always cheaper to buy software for 37,000 computers. If a piece of software costs $100, you could hire a programmer or two and save a few million.
Back on the platform issue, your claims about what the Mac can't do is short on specifics. Give us an example. Perhaps a better solution is available that you are not aware of.
The establishment of maintenance routines can bias turnaround in either direction. While each platform has its strengths and weaknesses which play into or against such routines.
Yet, Apple most hurts itself in the software area about which you wrote. The engineers and bean counters DO NOT want to go into an Apple Store and be greeted by "Have you seen iPhoto?!" quizzlings.
They want to see production machinery --- real tools.
And on that note, you nailed Apple to the fence.