Security is just a small reason why I use Macs. But I tell you what, in 8 years of using them I have never had mine down due to any virus.
In 22 years of using CP/M, MS-DOS and various flavors of Windows, I've never had a virus survive long enough to execute on any of my systems, much less take one down or even harm one. It's not all that hard to secure one's system.
Never used Macs; they don't run the software that I need to run and they're overpriced for what you get.
Security is just a small reason why I use a PC. But I tell you what, in 12 years of using them I have never had mine down due to any virus.