I think you are right. Furthermore, there are other endeavors besides sports where teens can become rich. Britney Spears was a millionaire at 17.
There does seem to be a "Young black kid from the hood ain't gonna know what to do with all that money!" kind of perception.
Personally, if I had the ability to earn millions right out of high school, I wouldn't think twice about it. College can wait. It would be a shame to suffer a career-ending injury while playing for free in college.