You guys have just pointed out the number one flaw of the education system in the US.
American 18 year olds graduate high school completely incapable of being adults. We shuffle them off to college for a few years to delay their entry into adulthood. And its bad enough to do that for four years, but a four year degree is now a five year degree.
Now we have an adult, being offered a huge salary, one that will set him up for the rest of his life, but he may choose to decline it (based on the advice of the adults around him) because he wants to be coddled a few more years?
Furthermore, are we not to believe that Nike wouldn't handle the basics of who to train under, who would in turn schedule his workouts, massages etc? And to that point, is being a professional athlete all that different from being a college student? No.