I completely disagree. While I do believe that genetics plays a part in giving a potential athlete a good starting base, I believe that hard work, practice, and attitude play a much more important part in "making" an athlete. I've been coaching for over a decade, and I would much rather have hard working athletes than supposed naturally gifted athletes. That's because the hard working athletes focus more on honing their skills. A person might be the equivalent of a genetic super athlete, but if they never practice and train themselves, they will be quickly passed over by other athletes.
Let's use Steve Prefontaine as an example. At one time, he held every American track record in distances between 2,000 and 10,000 meters. But by his own admission, he was told over and over again that he wasn't "built right" in order to run distance. Prefontaine became a great runner through sheer grit, determination, attitude, personality, and self-confidence. I suppose that you could claim that all of those characteristics are determined by genetics, but I believe those characteristics are more of a result of outside influences on a person.