It only rules in the same vain as a Bud Light drinker saying Coors Light is horse urine. It's brand worship hyperbole.
"Professionally trained" only applies to a graphics student when he is properly learning actual subjects in design rather than merely figuring out how to click around in Photoshop. The computing hardware is nothing more than a tool. It isn't some sort of magic cape that delivers super creative powers. The student must possess some natural talent. The teacher must have a command on the topic. It's not enough to merely teach applications. But that's what most places offering what passes for "design training" do.
It makes no difference what hardware a so-called design school chooses to run. If anything, the choice of putting Mac hardware on the desks is more of a marketing ploy to attract students. It subscribes to the stereotype that all professional graphics work is created on Macs. The kids get all the warm and fuzzy feelings of seeing Macs on the desks. They're less inclined to ask themselves if the person doing the "teaching" is even qualified to be there.
More hyperbole. The applications and periphreals are doing far more in producing the work than the operating system. A Mac based install of Adobe InDesign isn't going to do anything more or anything better than a PC running the same program and using the same fonts.
The Mac platform hasn't been superior to Windows in graphics production since the mid 1990s. Back then the Mac platform had superior versions of Adobe Illustrator and exclusive applications like LivePicture. Windows 3.1/NT/95 didn't have much in terms of color calibration tools. Back then graphics work was all print oriented. Then the web took off in popularity. So did 3D gaming and visual effects. Apple nearly went out of business before Steve Jobs swooped in and saved the company.
I think the Mac platform is in trouble again, and deliberately so by Apple's own doing. The company is making a lot more money selling iPods, iPhones and iPads to consumers than it is from catering to a niche base of creative professional workers. One of my friends who does professional video work is very angry over what Apple did to his beloved Final Cut Studio with the update from FCP 7 to FCP X. Apple doesn't care because dominating the personal computing market doesn't fit with their grand plan. Apple thinks it can get its rivals to chase them 100% into the consumer gadget market space, effectively kill off the personal computer workstation as we know it and have everyone using portable tablets instead. So far, I think their plan is working.
The user demographics aren't there for the virus writers to bother with making Mac-oriented viruses.
As of August 2011 the worldwide share of computers running versions of the MacOS was 7.31%; versions of MS Windows were on 82.5% of computer systems. Other operating systems like Linux, Sun Solaris, etc. have the remaining balance.
Most writers of computer malware are in it for the money. Windows systems are the biggest target. The vast majority of businesses worldwide run Windows-based clients. The Mac user base is a niche with a lot less money to steal. Students, young people and workers in certain fields (like newspaper publishing or video editing) represent the bulk of the OSX market. A computer thief isn't going to find much to steal by breaking into any of those machines. I guarantee if most computer users were using Macs there absolutely would be a lot of Mac-based computer viruses spreading in the wild.
OSX being UNIX-based is no guarantee either. Other UNIX-based things have been targeted by viruses, such as the Apache server under Linux. The folks at Apple aren't stupid enough to think their product is completely immune either. Proof of concept viruses have been made for OSX and the classic Mac OS. And Apple has indeed patched OSX with security updates on numerous occaisions.
Mac OSX was not engineered by some god or superhero. It was made by fallible human beings, just like all other operating systems and computing applications. Lots of computer software engineers and scientists have migrated between Microsoft, Apple, Oracle, Sun, IBM and various other companies over the decades.
All I can really say here is thank you for your post!
There's a lot of valid points throughout this thread, and, just like any Mac vs. PC thread on here there is also a lot of misconception which has been pushed forward through stereotyping and marketing ploys for nearly 20 years now.
Ignoring the entire Mac vs. PC debate and focusing on the original topic of integrating a single Mac computer into an all PC office. Wow. While this is possible, get ready for a lot more work. Not only are you going to have the extra expense of the computer system itself (and yes, the guaranteed higher cost of upgrading it so long as you keep and use Mac computers) but you now have to purchase TWO copies of all your software and all future upgrades: one that is PC compatible and one that is Mac compatible. The cost difference there alone is hard for any business to just shrug off.
Next you have compatibility to consider. As has been pointed out above, some modern software out there can pass file types back and forth easily, but there are a LOT that cannot, so you will have to be very careful about making sure what software is compatible with both of your systems as well as what file types work with both systems. Connecting up and sharing information on the network between these two different platforms can be challenging as well, it's not always just plug in and start grabbing shared files like it's sometimes made out to seem so simple.
As a local computer business, I've had a few different offices ask me if they could integrate a Mac computer into their offices just for a particular person. Once I start writing out all the costs involved, the extra steps necessary to try and make that computer system "play nicely" with the rest, and the changes that will have to be made company-wide to incorporate the upkeep, maintenance, software, and compatibility of that one different computer they just are dumbfounded. My only recommendation can be if you're going to go Mac, go ALL Mac systems, or just go ALL PC systems. Yes, it's possible to use both in the same environment, but you have to be careful and you have to know what you are doing. I'd highly recommend if you plan to do this that you also look for a reliable computer technician, either a single subcontracted technician or a trusted computer business, that can help you out because I guarantee his skills will be necessary for making things work right.
... Unless it's when i buy the custom made italian sandwiches for lunch :Big Laugh then i'm such a great boss 
