but as far as I know no one has come close to demonstrating a genetic racial component.
well, you don't know far! Read "Race, Evolution and Behavior" by Rushton, Race Differences and What They Mean by Levin, Global IQ by Rushton, anything by Arthur Jensen, Race: The Reality of Human Differences by Sarich and Miele...
and check out the thorough debunking of Stephen Jay Gould by the New York Times' Nicholas Wade.
http://www.nytimes.com/2011/06/14/science/14skull.html
But whatever. If you stacked the data to the ceiling on the genetic racial component, people wouldn't want to believe it.
People Refuse to Believe What They Don't Want to Believe -- Facts are Irrelevant
And I'll admit that 10 years ago, I did not want to believe it. It seemed too awful. But also an extremely powerful explanation for why things are they way they are.