When will we stop worrying about the superficial characteristics of our candidates for POTUS, VPOTUS, and SCOTUS?
Do you think that 44/45 presidents where white men because they happened to be the best people for the job?
No, but we've only had 14 presidential elections since the VRA went into effect and 2 of them were won by a black man. Black people are about 1/7 of the US population, so at least post-VRA, this is right in line with what we would expect to happen randomly.
On the other other hand, it's pretty remarkable that it took nearly 100 years after the 19th Amendment to even nominate a woman, considering they are roughly half the population and a majority of presidential voters in all of the past 10 elections.