Hmm, a few inaccuracies in Josh's comments regarding Jeffrey's comments.
"The typographical argument doesn't hold water either..."
Actually it does, Josh. Yes, type *clarity* is equal on a nice flat screen (I use OSX, OS9, XP and 2000 at work) and I can assure you, that MS has yet to match Apple in typography.
Can you type ligatures in a Windows system yet? No. Funny, Apple figured out (16 years ago?) that to make a lasting book, worthy of an Edward Tufte approval, you'd need those touches that make a piece professional.
Try this sometime, and see if I'm wrong. Type a document in MS Word on Windows. Print it out on a laserprinter. Now transfer the doc, or retype it on Mac Word and reprint it. Compare the two. Notice how the Windows version is full of rivers and has inaccurate spacing? Notice how tight and proper the Mac version is?
That's what Jeffrey meant. He's a designer. He notices those touches. Even Quark documents don't always print the same. It irks me to no end, but it's true. The tracking simply isn't as accurate, or on some apps, is completely ignored on a Windows machine.
Your suggestion, "it's just a matter of looking around a bit to find a superior program for almost every application a computer user would need."
Try telling that to the company head whose tight fists on the budget only wonder why the job isn't being finished on time. Professionals do not have time to hunt for shareware and plugins all day that do something a proper app can do correctly the first time.
Our managers (at least in mine and several other's experience) expect us to make do with what we have and question why we didn't buy the right program the first time. That's the world and that's also why my manager refuses to guve up Macs. He knows.
Live Coverage of Steve Job's 2004 Macworld Keynote Speech
AppleMatters Interview: Jeffrey Zeldman Talks Apple