This is a horribly dangerous belief... there ARE mac viruses in the wild and the mac system is ANYTHING but secure against attacks. It's not as common because it's not nearly as widely used. There is little to no security against them, though. The Mac OS is anything but revolutionary and wildly different from any other UNIX system.
Before you make such baseless and untrue statements, read the entire thread first. Plenty of proof has been supplied. Read and learn.