Its simple, Life's not fair.
Certain people either won the genetic lottery and worked thier asses off to get to that point. They live the good life and so on until one day career ending injury. Those millions made is now something different. Did that athlete have some kind of backup plan? Did he waste his entire life on the sport he was in?
Also, think of everything from the parking and food money to actually buying a ticket to see them play. You are the ones that ultimately pay these athletes.