You can fantasize all day long about how you think progressive thinking people of the 21st century ought to think. And, you can throw around stuff like "back ally thinking". But that doesn't make it any more than an ideal of how you wish things actually are.

Name me even ONE NFL player that had mental illness of any level or type that came back to an NFL team and played.
NFL teams can't afford to think in abstract ideals and in altruistic ways about its players. It's a business. And are they going to bet $1mil and a roster spot on a guy who is trying to recover from some sort of mental illness (assuming that's even what it is)? Especially on the QB spot that requires rock solid leadership, a strong mental state, and the most emotionally stable of all the positions?

I don't think they will, and I doubt any NFL team will beyond a PS place at best and even then it may take at least a couple years of prove it to ever give that guy an actual shot at contributing on the field in games. My crystal ball says if he ever plays pro sports again, it'll be the Canadian league or something like that, and then, who knows, after enough time has passed maybe he gets another shot in the NFL.

Again; I'm not talking about how things perhaps ought to be, but rather how they are in the real world. And without some evidence within the NFL world that QB's come back from mental illness to play on NFL teams, then all you are offering is a wish.