I think there's a couple of reasons that this won't kill football, as gruesome as it is. The first is how much money the players make. Most people will assume that they know of the risks, and that the millions of dollars made during a career will offset that. It's hard to develop sympathy for a person playing a game for a living and making that much money off of it.
The other reason is easy: apathy. How many people will watch this, be horrified for a night, and then continue watching football under the premise of "well, there's nothing I can do about it"? It's hard to stop an industry as large and powerful as professional sports, especially when they're blatantly against something.
That said, I think it's horrible how physically and mentally damaging football is. Despite me occasionally watching it, I will always be a much, much bigger fan of baseball.