I've had this discussion before: One reason you don't frequently hear about founders that are women and minorities is that journalists don't go out of their way to point out the physical characteristics of people. To do so would itself be potentially prejudicial.
To use your example, if a company is run by a black woman, no responsible reporter is going to put in their article "Oh, and by the way, this company is run by a black woman." Just think of how negative that sounds.
