NFL players claim they need all this money because their average career is 3.7 years. Well after 4 years, in my opinion, they can fall back on the degree they earned from college. Wait a minute, half of them come out of college early to pursue a career in the NFL...well, then they can be treated like any of the other DROP OUTS in America and scrape a living like the average American...do you realize that 1000 of the 1850 NFL players make 300k a year (league minimum)? If the average American makes 40k a year, they make in one year what we make in almost 8 - or they make in 4 years what it takes us 32 years to make!!!
That was just the "simple" math. Let's take this out to year 4.
At the 4th year, a league veterean is guaranteed 625k per year. Anyone making league minimum after 4 years is probably a situational player like a punt returner, special team player, kicker, dime back, etc. Those 32 years I mentioned in the first paragraph is probably more like 45-50 years in actuality. Now, an owner sees that he is paying 1 person 625k to play special teams...why wouldn't he cut that player and get himself 2 rookies for 600k (300k each) and hope that one of them plays as well as the 4 year vet? It only makes good business sense.
That is the primary reason the careers are only 4 years long. Sure, there are injuries that end careers - but in the end, the players (and the unions fighting to get them all they can) have priced themselves out of the market.
Note: all money numbers came from ESPN radio Wednesday night (7/20).