Black people only make up 13% of the population. [1] Most people forget this fact when judging race in a population. 1) http://en.wikipedia.org/wiki/Demographics_of_the_United_Stat...
Asians and those from the Middle East have an even smaller percentage but appear to be well represented in startups.
That said, I'd argue that unless you grew up with computers and were interested in programming them early in life you probably aren't the startup type. Your income level affects this, obviously if you can't get your hands on a computer then you're not going to be able to do much. As a geek I never had any "role models" or other things that set me on my path. Nor did my parents encourage tech. Nor did my friends. I was, and in many ways, still am something of a lone geek amongst non-geeks. I believe "role models" to be a meaningless cop-out.