> If this was a meritocracy, you would expect a proportionate number of every ethnicity and religion represented in the workforce of large corporations.

By this logic we should expect the NBA, NFL, NHL etc. to look like a random sample of the US population. If the source subpopulations differ by even small amounts on mean or variance those on the extreme tails of distributions will look very different from the general population. So the ranks of men who have ever run 100m in under ten seconds are basically all black and elite marathon runners are about half Kalenjin, an ethnic group of fewer than ten million.