It's interesting to see the same arguments being used that always come up when someone asks "PC or Mac".
Viruses don't automatically appear on Windows-based PCs, it comes down to the user. I've used Windows for over a decade and never had a virus, but then I'm careful about the sites I visit, the things I download, the links I click and the things that I put in the computer. I have a decent firewall, whose warnings I actually read and evaluate, and I used anti-virus software.
I've never had a serious problem with my computer crashing. I had recently because of some problems with a TV tuner card, but that was a hardware problem.
Even when I used Windows Me, I never had huge problems. Obviously, I've had computer trouble, but I'd be very surprised by anyone who hasn't had some sort of computer trouble, even with a Mac or with Linux.
I've also used Linux (or GNU/Linux if you prefer), which took a little getting used to. If I didn't use Photoshop, and didn't play games, I would happily use Linux all the time, but at the moment, the GIMP isn't quite at the point where I'm willing to ditch Photoshop altogether.
As for a Mac's ability to outperform a Windows PC, I think that's largely down to the hardware. Granted, the integrated media software that Mac has is excellent, and facilitates productivity, but Macs also come pre-packed with pretty high-end hardware, compared to most PCs. Which accounts for the higher cost.
If I were to buy a Windows PC of the same specifications, I don't think that Photoshop would be noticeably different between the platforms.
But, as far as I know (and I could be wrong), the hardware available for Macs is limited. I'm sure there's plenty of great hardware available, but the Mac OS has the improved security and stability because it's made for a limited range of hardware, whereas the Windows OS is made for a much larger range of hardware, which is sometimes the cause of problems, but it does make Windows PCs more accessible - you don't have to spend a huge amount of money to get a Windows PC, which can do more than most people will need.
Since the way in which everybody uses their computer will be different, people are going to have different preferences.
If I want to play the latest games, I'll use a Windows PC.
If I want to do photo/video/audio editing, I'll use a Mac.
If I don't want to do either, but want a system that's secure, stable and powerful, I'll use Linux. It's much more customizable, too, and depending on your level of proficiency, you can install an operating system which is highly optimized for your hardware.
Aside from games, there isn't anything I can do with Windows that I can't do with Linux. And if the GIMP ever gets some of the more advanced features of Photoshop (adjustment layers being the main example), I might consider ditching Windows. Also, it's been a while since I last used it, but I really dislike the separate windows that it has/had.
I've never actually used a Mac, but I do know that they're preferred by most people who edit audio, photos and/or video (I know a wedding videographer who uses one for those tasks). And the nature of the software is appealing, but it's not something that most people are going to use on a day-to-day basis, so it's hardly worth mentioning as an argument for why Macs are better than PCs. They're also too expensive for most people; most people don't need the power of the hardware that you get with Macs.
With gaming on the PC; there are always video game consoles, which are designed specifically for gaming, so anyone with a Mac could easily go out and buy one of those for gaming.
A million dollar sports car is not going to be any use to a family who need space for children, pets and shopping, and similarly a family car isn't going to be any use to a racing driver.
A Mac is "better" if you need the power of the hardware. And the media-editing software is arguably better than what's available for Windows.
A PC is "better" if you don't need all that power; if you just want a computer for browsing the internet, using email, doing homework/writing reports, basically anything that doesn't rely on extreme CPU and graphics power.
Besides, I can spray my PC white and paint an Apple logo on the side for much less money than acually buying a Mac. That's the only reason people buy Macs anyway, isn't it?