This isn't about an accidental head injury, it's about adults - the coaches and any trainers, etc. - ignoring signs of injury and pushing a child to play through injury.
It's too bad that it took an injury of this magnitude and a lawsuit, but maybe this will send enough shock waves through the youth football system to get everyone - at every level - to understand that the health of the players comes before the team, always.
My boys all play hockey and my step-daughter trains in a variety of fighting styles, from traditional karate and boxing to mixed martial arts. Of course the thought of head or spinal cord injuries is on our minds all the time. We've been lucky so far that all of the coaches and trainers that we've worked with take head injuries very seriously. My oldest son was waived through a round of tryouts for a hockey team last year because he had gotten a mild concussion in gym class the week before. The league would not allow him to set foot on that ice without clearance from his pediatrician. They would have arranged a private tryout later if needed. We have kids sit out games all the time, even if they want to play, if there is any question of injury.
It sounds like in this case, the boy had symptoms of injury and voiced his concerns several times and was ordered to play anyway. That's negligence, and that's why the school district settled.
I don't know about every sport, but I know that in order to play hockey or lacrosse, all players have to pay annual membership fees into national leagues that, among other things, insure the players in the case of catastrophic injury.
And your comparison to a broken leg is callous - this boy has lost complete, permanent control of his body forever. His life as he knew it is over, and this could have been prevented. That's what the lawsuit is about.
ETA: in response to your SWH...if course no one thinks they intentionally put the kid on the field to then suffer from a life-changing trauma. It's about NEGLECT. There were clear warning signs that COACHES, who are TRAINED for this, should not have ignored. Clearly you don't get how sports works, especially "tough" sports like football. If the coach tells you to play, as a general rule the player gets out there and plays. Do this boy and his family wish that he hadn't? That he spoke up more, bucked the system etc and insisted on medical care? Sure. But it was the responsibility of the trained staff to recognize injury and insist that the boy to seek treatment and not return to play without medical clearance. This type of thing is in coaches training, every year, from 6-year-olds suiting up for mite football to high school, college and professional players. There is no excuse for the coaches to ignore the signs and tell the kid to play. That's why they settled - they knew that they were responsible though negligence, not intent.