For example, companies not having a universal test for talent does not imply talent does not exist.
The Polgar sisters are interesting. However, their parents were very intelligent, so it is unknown if the same approach would also work for children of "less intelligent" parents (if such a thing exists, as supposedly we can't measure it). And studies in that line of thing seem to point to children starting a specialty at an early age (see Ericsson's book "Peak"). So unless you can repeat the experiment with some older people (make somebody a chess genius at age 30 who has never played chess before), it doesn't really matter what part is nature and what part is nurture. You still have people with different talents applying for your jobs. I mean the Polgar sisters ARE better at chess than other people, and there probably isn't an easy way to hire somebody as a chess player and bring them to the level of the sisters.