One has to wonder, then, why they didn't hire you.
I have a theory. It's quite cynical, but it's taken me about 5 decades to arrive at it: life is a beauty pageant. I don't say this lightly. It was a very slow process to get to this point.
A friend, colleague recently interviewed at a very popular, pre-IPO company that is often discussed (positively) here. He doesn't look like your typical engineer, but he's literally the smartest person I've worked with. He gets shit done. He learns new things all the time. As his current manager, I told him I would give him a perfect recommendation. He had an "in" with a current employee. He aced 5/6 of the mini interviews, but "failed" one. Fine, it happens. But, something he said to me stuck in my head: the building of said company was filled with rows and rows of 20-30 white kids. He saw 2 people of color, and one was a greeter at the front door.
I don't believe the people that interviewed him were racist, but I think every person applies a "does he/she look the part" filter and if the answer is no, the mind finds reasons to not hire.
It's not just hiring that I think is pageant-like. So many things in life are. So much so, that I think people themselves actually live up or down to their physical features and characteristics. Look at the executives at a F500 company. Male and female. Why do they look so similar? I live in a somewhat affluent community. Why does everyone here look like they "belong"? This is not a gated community, so why does that happen?
Physical features are such a basic filter, applied to ourselves and others, that I don't think we are hardly aware of it.
EDIT: there are always exceptions. It's been my experience that exceptions are rare, though. And the exceptions sort of prove my point.