I think you guys are forgetting how much it costs to have an agent, lawyer, financial adviser/accountant on retainer costs that gets tacked on to all the other shit that normal people have to pay as well. And while the adviser/accountant aren't getting percentages of your pay the agent and lawyer are. While I can't speak for Brutul I am guessing that is why he suggested broke, as they did cover that in the 30 for 30.
Yeah, and that's not everything. If you make 10 million, start by sending half of it to the government. Then send a chunk to your agent. Now with what you have left you're living in a culture where you're expected to party like a rich guy, live in a swanky house, give money to charity, drive a $100,000+ car, make it rain at the strip club, etc. Most of these guys are in their early 20's and don't come from a background where they know anything about money. All of their friends and family are coming to them thinking that they have unlimited money and they should share it, and there is a thing where if the local kid makes good, he's supposed to bring something back to the old neighborhood. There was one guy on "Broke" that bought houses for like 5 relatives. Not paid cash, but actually took out mortgages for 5 houses that he was not living in, and the people he bought them for were pissed when he got injured and had to sell the houses because he couldn't make the mortgage payments.
Then after you get past the friends and relatives, there are a whole lot of shysters coming to them claiming to be financial advisors, entrepreneurs, charities, etc. that want them to invest in a restaurant, a bar, some internet company, etc. and they take their money and then either don't do anything at all, or piss it away on some business that they don't know how to run. It's easy to say that they should have known better, but how many 22 year olds are really good with money? Regular 22 year olds are just running up their $1500 limit credit cards and buying used cars that they can't afford. Give those people millions of dollars and they would really fuck things up.
On top of that, it's just in an athlete's mindset that they are going to play 10-15 years in the league, but most of them will be out in 3.
Now if you gave me 10 million dollars today, I would be set for life, but these young athletes are in a much different situation and it's surprisingly easy to wind up with nothing to show for their ride in pro sports, which is what happens to a lot of guys.