I love seeing history repeat itself.
Years ago, it was OSX that was impenetrable. "Find us an active exploit or virus", they said, "and dont give us any of that market share nonsense". All the while the clues were there, with OSX getting exploited in seconds at Pwn2Own when actual cash and computer swag was on the line.
Here again, we have an OS with a minute market share boasting about its impenetrability and lack of exploits. I might propose that a great deal of the lack of exploits is the lack of any real incentive to go after such a tiny group of OSes which are invariably set up by fairly skilled IT persons.
Develop a BSD distro with a desktop environment and a modern web browser, and set it out for a million end users to use with a $50k cash prize for the first exploit, and you'll be paying out in a day, tops.
The amount of arrogance in some of these "My *Nix is best" threads is staggering. There is NOT code out there that is significantly more complex than Hello World that is bug free.