Only thing safer helmets will do is encourage players to hit harder and harder, until someone really gets killed. I hope one day I will get to see the end of football. Why would any parent enroll their child in this sport?
There are several sports than can be dangerous and involve risk of death, like basically all forms of racing, climbing, endurance, etc. As long as practitioners are educated and consenting, I don't see a problem. The problem is if the those responsible for the athletes are not upfront on the risks, or if the athlete is not able to make a proper judgement to consent, like a child.
Up in Canada the pro-contact hockey crowd loves to talk about "teaching kids how to hit properly" which I'd suspect is a similar attitude to those coaching 5-yr-olds in full-pads football. But what does this mean? They seem to think that by addressing the technique of what is at it's a core a violent and damaging activity you can somehow mitigate the effects. I'm not buying it. Football is even worse; it's not the highlight reel tackles but the every single play collisions at the line that lead to long term, consistently demonstrated traumatic head injuries.
Frankly I feel that the NFL working to address the root causes of head injuries is like asking Facebook to take care of personal information and privacy protection. They are entirely incompatible.