I have no sympathy for the players. They have rejected safety advances again and again (like the better helmets) because it affects their performance and thus their ability to get paid.
Look at the 'bounty' thin happening. The NFLPA isn't protecting the players who were targetted, they're protecting the guys who tried to injure other players.
I have a hard time believing the the players back then were 'less greedy', but just didn't have the opportunity to be so.