The only thing that silicon valley has that the rest of the country doesn't is access to crazy investors. People who will dump money onto the flimsiest of ideas flock to Silicon Valley to gamble on the next facebook, amazon, or ebay. The developers there aren't any smarter or talented. They lack discipline and ability to focus on something for longer then a few months.
Zuckerburg isn't the next Einstein for stealing ....creating Facebook. He simply won the lottery with a halfway decent idea that captured peoples interest.