This analogy makes no sense particularly b/c if you paid them enough people probably would start their day by running head-first into a wall. I mean, you've seen jackass right? But even so it's a grossly inadequate analogy, at least if you were intending it to further your point.
No kidding but there is a long way between "some lingering effects of concussions" and "full-blown alzheimer's at 50" or "a string of crimes culminating in a murder-suicide stemming from severe clinical depression." We're not talking about whether or not hitting your head is a good thing. We're talking about the severity of the ramifications.
I don't even know where to start. First of all, you're backwards. The list of lingering football injuries were not only well-documented, but a badge of honor for many of these players. The effects of concussions were not. I mean, I honestly don't know how you'd argue that everyone was so well-aware when even 5 years ago everyone was using the cute phrase "getting your bell rung" and sending players back onto the field in the same game with the consent of the team doctor. If your team doctor is saying, "You're all good son, but if you want to tell the coach you don't want to play, then ..." then you're playing and you're certainly not really informed of your condition.
Secondly you seem to be ignoring the fact that these players wear helmets which they thought were cushioning these blows. Right? Isn't that the whole point of the helmet? Little did we know they weren't doing a thing.
The bottom line is this: Yes, playing football is bad for you and has inherent risk. Yes banging your head on a wall is bad. No, I don't think an employer has to foot the bill for everyone's health care, etc.
However, if you run a league where you not only encourage violence but you encourage players to ignore injuries and continue playing AND you have medical staffs that somehow sign off on this as perfectly fine protocols, then you should feel compelled to help these guys out when it is discovered that there is an alarming rash of traumatic brain injuries. You should also change your practices (which the NFL is doing) and at least educate current players on the risks and the importance of long-term health insurance. I'm not even really sure what the debate is with any of this.