Blame God I guess. And it isn't about whiteness though it is unfortunate we carry the gene for the most part.
The Nazis were wrong when it came to genetics. They presumed purity of race was possible. We know that isn't true now. But they were right about purity in general. Not racial hygiene, but mental hygiene.
It is possible to build a better humanity by only selecting genes that highlight lessened aggression, cooperation, cognitive flexibility and searing logic. A humanity removed of its superstitions, prejudices and irrationality would finally unlock the true potential of the genome.
A beneficial side effect of all this is reducing the strain on the planet. Within 50 years we can reduce the population by 50% by simply sterilizing those whose genetic contribution is not beneficial.