weeks - 7:25 pm on May 1, 2010 (gmt 0)
Most of the better-informed people have greatly discounted the idea of Mac's virus protection coming from the lack of market share of Apple computers.
It's not just one thing that has made Macs more secure, so it takes time to explain. And people prefer simple and easy to understand answers. And, there is a tad of truth to your market share argument.
Here's one writers careful look at the issue:
Thanks to its extensive use of battle-hardened Unix and open source software, Mac OS X also has always had security precautions in place that Windows lacked. It has also not shared the architectural weaknesses of Windows that have made that platform so easy to exploit and so difficult to clean up afterward...
One reason I like that somewhat aligns with "market share" is that since Mac's are typically more expensive, their users are typically better educated and more sophisticated, wisely avoiding viruses. Mac users are better looking, snappy dressers and funny, too, of course.
But, I think it could happen some day. And long-time Mac users are completely unprepared emotionally to handle a serious virus on their machines.