You are not getting that they are suing for better healtcare. They aren't getting adequate care after retirment (the players who played 10-20+ years ago). That is what the lawsuit is about. The NFL isn't going to do anything until the lawsuit goes through. That is the only recourse that these players have to get what you now admit they need. How many stories of guys who have dementia that have no health insurance and no money left to pay medical bills do you need to hear? Most likely this will turn into a class action lawsuit and each player will get an amount, not 10 million each.
To your point, I doubt there is anything in their contracts that says they agree to get brain damage.