That myth is pure Microsoft propaganda. Most folks know that Macs are better than Windows PC, but said that Macs were too expensive for their budget. Now that Apple is selling a $499 Mac, a lot of Windows users can afford to upgrade to Macs.
By the way, the article at the top of this thread ("Apple: Here to Stay") was written by Don Tennant, the editor-in-chief of Computerworld. If you're not familar with the publication, it is the most trusted news source for senior IT professionals for 37 years. Frankly, Tennant's credentials to ascertain the commercial viability of Macs are far better than Last Visible Dog's.
Plenty of astroturf on this thread, eh?
Do you have supporting evidence for this MacMythology claim or do you want us to just take your word on it? The fact is Apple has held 3% of the market for about 10 years and there is no data that shows this will be changing soon. Apple comes out with newer doodads every year and the MacMythology machine churns out statements about great sales numbers yet their market share does not budge. Clearly the Apple 3% buys whatever Apple tells them to.