I've written about this before here. If you want to blame something for the problem the culprit is obvious: antibiotics and good nutrition. It used to be that nobody - and I mean nobody - grew to the full extent of their genetic potential. My mother had typhoid fever when she was 12 and almost died. Her father died of influenza after WW1. Now, we worry about people getting sick as they get old. And the kids get to grow to their full size and strength.
Result = a massive basic physics problem for modern football. I played in high school and college in the mid 60s. The largest player I ever faced was Charles "Buddha" Slayton, all 5'11", 255 lbs of him. The Buddha was easily the biggest player in Atlanta; today, there are 8th graders that big. If you have a collection of young, fast, well-trained men who typically weigh in the 230 - 320 lb range running around a field hitting each other, you will have injury problems. Provide them with helmets and protective gear for their head and neck and you'll have them running into each other full speed and head first. (Charging penalties for head to head collisions won't stop the damage, btw.) And - surprise, surprise - you end up with an epidemic of head injuries and the longer the young men play the worse it gets.
This won't "kill" football; the sport is too engrained into our entertainment culture. But it will, as pointed out above, choke off the supply of football players over the long term and relegate the sport to a much less prominent role. If I had faced the choice then, I would have discouraged my son from playing, though, as it turned out, he liked lacrosse better. If I had to predict what will happen, I'd guess that we'll see rugby beginning to catch on more here. It's a rough sport, but the lack of helmets and pads leads to a different kind of play with fewer major injuries. But football will never go away.
One other thing: as concern for head injuries goes up, I wouldn't be surprised to see more emphasis on amateur pro leagues. The colleges will slowly become less accommodating and the pros will do what they do in Europe: start teams for young people who a) really want to play football and b) really don't want to go to college. Here the equation become simpler: you know the risks and you voluntarily took them so you could get a chance to play pro ball. This used to be a regular way to get into the pros in the early days (the AAU was a main source) and could easily come back.
I'll miss big time college football as it diminishes. I really enjoy watching the game. But I like boxing too and I'm glad it is no longer taught in high schools or a part of high school or college athletics (it used to be huge). I see the same trajectory of the college game and, perhaps, for the pros.
