I don't think the damage there is as immediate as NFL players being basically legally incompetent and unable to take conscious decisions. It's probably more likely that they have no experience of managing a budget, saving for long term and planning their future - a trait shared by many people who never ever put a foot on a football field. And when you get $ton-of-money and have no experience in managing your finances, pretty soon you're broke. Look up the statistics of the gold rushes - a lot of people coming into sudden wealth got broke pretty soon, and didn't need any hitting on the head for that to happen. The percentage of people that got wealthy and were able to keep it long term is depressingly low.