I don't think the point of the article is to say "don't do sports". It's more like "be reasonable about what you want to be". It's not reasonable to expect to be a pro basketball player. The mathematical odds against that are pretty great. The odds against being a scientist are extraordinarily low -- an interest in things of science and a reasonable aptitude for science are pretty much all that's required.
That being said, talking sense into kids sometimes, especially when shattering their dreams of becoming the next Shaq, is completely useless.