People have always known that football is a dangerous sport, and those who choose to play football (and parents who let their kids play) make that choice willingly and knowing sports carry inherent risks (every football sign up sheet I've ever seen contains a very explicit description of the risks associated with the sport, as they are currently known). Now as it turns out, those risks were worse than we thought they were at the time, but that's really news to everyone at this point. But even with the risks as known in the 1990s, I went to school with plenty of kids who had parents that wouldn't let them play football. That was a family choice. I say let each kid/parents draw that line for themselves. I mean the risks of football, even with our increased understanding of CTE/concussions, are no greater than the risks of bike riding.... are you going to let your kid ride a bike? Will you make them wear a helmet? If you keep your kid from playing football or riding bikes or doing anything that might give them a concussion, what are they going to do with their free time? Sit in front of the TV playing COD and chugging dew? HMMMM
For me, the only "line" that needs to be drawn, from a legal perspective in regards to a high school sports association, is if it can be proven that the organization intentionally hid information or published misleading information regarding the risks associated with the sport. If we were to find out that the organization intentionally hid information from parents/players, then I'd say the line has been crossed and they are legally responsible. As far as coaching responsibility, there are some sadistic fucking coaches out there (I had one who would hit us on the helmet with a hockey stick when we messed up), and if they are giving the kids concussions by doing ridiculous and abusive shit, then they absolutely should be legally held responsible for that behavior. I think those are the exception, and generally speaking I think coaches try hard to be conscious of concussions, but most are out of their depth when it comes to evaluation.
From a corching perspective, as a Pee Wee and Middle school coach with no athletic trainers/team doctors around, I was given way more responsibility than I was really comfortable with in regards to evaluating player health. I don't really give a fuck about winning compared to player health/fun/enjoyment (I realize I'm probably in the minority on this, even among Pee wee coaches). I always made sure everyone had proper fitting helmets (most volunteer coaches can't even do this correctly) and we talked to the kids about what a concussion feels like and what they should do if they get hit hard in the head. Beyond that we did no full contact tackling drills in practice (freeze and fit tackle or "thud" tackling drills work better anyway) and we limited full contact scrimmaging to maybe 15 minutes per week in a confined space near the goalline (less open field running start tackles). From a coaching perspective, I think I did all the right things to help avoid concussions (mostly by practice planning) and to look for signs of concussions, but in the end there is only so much you can do to avoid them.
If I thought a kid had a concussion, and sometimes it is incredibly obvious, I immediately removed them from the game/practice and they didn't go back in. Sometimes it isn't as obvious and a kid would look normal to me and then his parents would take him to the doctor and he'd be diagnosed with a concussion. If I did suspect a concussion, I would always attempt to inform the parents and ask them to take the kid to a doctor for further evaluation, but frankly I coached a lot of poor kids and never saw 75% of the parents for the entire season. Even calls and emails go unanswered. What do you do in that situation? How am I, a volunteer coach with no medical training and no medical support, supposed to evaluate this kid and decide if he can come back and practice the next day? This is something to keep in mind if you have your own kids in youth/middle school sports, are you going to rely on the judgement of a volunteer coach who watched a 2 minute video clip about concussions?
Would I let my own kids play football at this point? I certainly wouldn't push them to play the sport, but I also think I'd have a hard time telling them no if they really wanted to play. I still think the physical benefits I received from football likely outweigh the physical harm of a couple concussions (my first concussion came riding my bike as a kid!). I would certainly be more involved as a parent (poor coach, lol) than most of the parents of kids I coached.