A Sport Worth Playing?

After over a week conducting research on my junior theme topic, (Why doesn't the NFL do more to prevent players from concussions) I have really started to truly understand the seriousness of concussions.  Back in my sophomore year of high school I sustained a concussion during a basketball practice.  All of the "stupid" protocols really started to aggravate me, mostly because I felt completely fine and wanted to start playing again.  Following research however, "stupid" was indeed the worst word I could have possibly described the standard concussion recovery process as.  

Sports broadcaster and writer George Stroumboulopoulos conducted a research with the University of North Carolina at Chapel Hill that the average life span of an NFL player is 55 years of age, nearly 22 years less than the average U.S. population as a whole.  Along with this reduction of life span is an increased percentage of having Alzheimer's (37 percent higher rate than average) after retirement from the league.  Most Alzheimer cases are diagnosed in humans over the age of 65, however many NFL players have experienced the disease at an age as young as 35.  

Sports columnists all over the country have opinions that the NFL is an economic devil, with owners using players as tools to their success.  Gregg Doyle of "cbssports" even quoted the NFL and its owners as "cold-hearted bastards", who to them, "players aren't people. They're commodities to be bought and sold, acquired and released. They're pieces in a brutal game of chess that has seen 273 players placed on injured reserve this season."  In my opinion, the people that would disagree the most with Doyle are NFL players themselves.  

If career ending, and possibly life ending injuries have been a proven outcome for many players of playing in the NFL, why do players still take up careers as football players?  Also, does the NFL have a bad influence on younger athletes and their decision making when it comes to their health?  The concussion issue in the NFL has begged many questions, those above being the most interesting to myself.