Personally, as the father of a 5 year old, I will not allow him to play football (and he's expressed an interest, but I will not cultivate that interest). Flame away.
I have some chronic degenerative neck problems and was seeing a neurologist for associated headaches. We were speaking casually about the football concussion issue and he was telling me that there is just no way to protect against it or, predict who will suffer. In other words, for someone, it can be one good hit, for another, it could be multiple hits. And it's not limited to football, it includes other contact sports (lacrosse was one my neurologist mentioned; his own son suffered 2 concussions playing) boxing, mma, rugby, and even "heading" the ball in soccer is now a known risk.
I don't necessarily believe it's the high-end vicious collisions that the average fan loves that's necessarily the problem, although those are inarguably dangerous. Just getting your bell rung is a risk and "getting your bell rung" probably occurs very frequently, including games and contact-practices.
Is the game getting "watered down"? Meh. We all know they are doing a lot to protect wide receivers and in reality, that was probably necessary. They are very vulnerable at times and you can still tackle the damn guy without trying to take his head off. They have shortened kick-offs in an effort to reduce the distance on returns, thus reducing the velocity of the players colliding over distance. And they will probably continue to make changes and I'm sure there will be equipment improvements as well. Will any of this stop the continuous "dings" to the head? No. Are the continuous "dings" to the head a problem? Apparently they are.
Will shortening the season help? Doubtful. A player coming up thru the pee-wee leagues, high school, college and then a few years in the pros has probably had enough "dings" where he'll either suffer the damage or he won't. They have seen the type of brain damage in very young players as well as the older retired players.
We all know football is inherently "dangerous". We can now add that football is a known risk for brain damage and will continue to be based on my understanding of the current medicine and science.