It always reminds me of the Japanese attempts to diminish the status and history of the Ainu, a caucasoid racial group from their northernmost islands.
Extensive research and data now point to the Ainu having lived on those islands from long before Chinese people first sailed to Japan and populated it - making the despised Ainu the true, actual Native Japanese.
It is appealing because it justifies racism. It is just the contemporary version of polygenism of racial science.
That said, even if human evolution is more complex than simple out of Africa, all of humanity has a lot of shared ancestry and genetics do not support the concept of race.