Not to be too much of a pedant, but: Turkish-Germans make up only 2.1% of the German population and while France doesn't have hard numbers because it's illegal to survey on the basis of race/ethnicity, estimates are around 7% of the population.

American blacks make up nearly 13% of the population in the US. That's a pretty significant difference and if you include all minority groups, America's a significantly less homogeneous place than any country in Europe or Asia that I'm aware of.

I agree with your (unstated) premise that this isn't the point, though.