Adapt or die. That's how football has worked.
The NFL is a huge passing league, sure, but there have been moments (in the last decade) where defenses have won out. Go back to the Greatest Show on Turf and it's funeral at the Super Bowl they lost to the Patriots. The Ravens won a Super Bowl with an incredible defense and not much else. Ditto with the Tampa Bay Buccaneers a few years later. Offenses took over again for a few years, including the 2009 regular season when the Patriots turned the NFL into a video game for a season, breaking records every week. But what happened in the Super Bowl? They got their asses handed to them by the New York Giants, who punched them in the mouth every single play.
And God forbid the NFL try and save the lives of its employees. One of my favorite players from that famed '85 Bears team was a player who shared my first name and also went to my favorite college: Notre Dame. His team is going to the White House in a few weeks to be honored for their SBXX win. He won't be there, because he blew himself away with a shotgun, and there's a very good chance his time in the NFL contributed to his mental issues. I don't want to be reading about the suicides of Brian Urlacher and Lance Briggs and Devin Hester and Matt Forte in 20 or so years, do you?
And you referenced the NHL as the "only professional sport" left, but they're doing the EXACT same thing with their rules: cracking down on hits to the head. Does that make it any less of a game? No. They're just trying to make sure Derek Boogard and Mark Rypien's stories don't happen again.
You say degradation, I say it's evolution. The game changes, both on and off the field. Just because you may not like it doesn't mean it's bad for the game.
