Ethnicity has been said to be highly important, and others have used equally bad slippery slopes to prove their point. This was a response to that. You haven't been following the whole conversation.
What has also been said by some is that a white people can't compete with the best East Africans, even the outliers. It's been stated in this thread that a white person can't run 2:02. If a white woman can run 2:15 why can't a white man run 2:02.
Straw man, but Mara Yamauchi, Véronique Marot
Quoting the nationalities of the top 25 list says NOTHING about nature vs. nurture.
The list of World Cup champions would suggest white people are better at soccer but you'd be an idiot to conclude that is because of genetics.