Jetservice - I like your response.
If you mean how come there aren't many models out there...it was the many models that almost killed Apple as a company. The company was re-organized under Steve Jobs and when the iMac hit the street and the models were streamlined, the company started to make more money. Now, Apple's biggest hit is the iPod.
If you mean how come they hold such a small percentage of the market... would you rather drive a Ford Taurus or a Mercedes E320? They both hold 5 people, both have 6 cylinder engines, and both can get you from point A to point B. It's all about potential lifetime problems, security, and reliability that you would buy a Mercedes (or Apple) over the Ford (or Dell, IBM, Gateway, Compaq...take your pick). How many viruses or trojans have you heard of involving the mac os?
People used to have fits over the fact that in the mid-90's Apple only had 5-7% of the marketshare. Mercedes and BMW have about 2% marketshare in the US...not bad, huh?
You land a million planes safely, then you have one little mid-air and you never hear the end of it - Pushing Tin