http://www.pbs.org/wgbh/frontline/film/league-of-denial/I think the movie is mostly a luke of a pbs frontline story done back in 2013. If you have a couple of hours it's a good watch. Mike Webster was my idol (I played center in high school) so that part of the program is sad to see how his life ended. The doctor Will Smith portrays is interviewed extensively in this piece.
My last 3-4 years of youth coaching every player was baseline tested. We were required to report any suspected head trauma (practice/games) and kids had to retake the test and be cleared to return to contact. Awareness and attending clinics totally changed my approach to contact, etc. When I started coaching I was very 'old school' about hitting every practice. By the time I was done we only hit maybe 1-2 times during the week with the balance of practice focused on form tackling or technique. Seldom did I see youth players concussed by mario smith type hits. It was usually heads hitting the ground after losing their balance or secondary blows in scrums. I would not have a problem with not starting tackle until maybe eighth grade or high school. Flag football can still have a physical element to it, and technique can taught and reinforced that de emphasizes the use of the head.
My last year in FCCJC I think we had 110-120 teams 3rd-8th grade. I just looked at last falls standings and there were less than 90 teams. Now there are competing youth leagues, and economy is having some impact. However, I do think the concern over concussions and alternatives (soccer, lacrosse) are drawing kids away from football.
One of the best known kc area high school coaches told us at a clinic he limited live contact each week to 1 tackling drill and 1 live scrimmage. I have read where some college coaches do the same. Even aware of one who live tackle without helmets to reinforce removing the head from the tackling process. I think coaches at the amateur level are very aware of the concern/risk and are adjusting accordingly.
I have a son who is now playing college football. He has been concussed twice, once in youth ball (my tackling drill), once in high school (half speed blocking drill). FWIW, he is 6'5-300 so he wasn't a small kid getting trucked by someone in beast mode. I do think about this and whether or not he will suffer any effects later in life.
http://www.amazon.com/death-American-game-crisis-football/dp/0316887358/ref=la_B001ITX9YQ_1_7?s=books&ie=UTF8&qid=1449031213&sr=1-7The Death of an American Game was printed in 1979. My mom bought me that book to try and discourage me from playing. IIRC this book argued the equipment was poor and safety rules not sufficient given the number of players being paralyzed or suffering severe joint (knee) injuries along with concussions. The issue has been around in some form for a long time if not as well publicized as it is now.
Tom