Just 'cause, that's why

Rico says he continues to be amazed that august publications like The New York Times, among others, fails to use the serial comma.
Why is it important, you ask?
As Rico's former Apple workmate, Rani Cochran, once pointed out, it can make all the difference in the world, as this actual book dedication shows:

She wanted to thank her parents, Ayn Rand and God.

Now imagine another comma between Ms. Rand and the Big Guy in the Sky...