NFL players hate it and the fans hate it.
Just ask Clinton Portis, Trent Green, or Shawn Merriman if they are supporters of the season before the season. Clinton Portis in '06 busted up his shoulder in the preseason and ended up only starting 7 games for the Skins. Green and Merriman both shred up their knees before the '99 and '08 season. Green was never the same, even though it turned out to be a blessing in disguise for the Rams and Kurt Warner. Merriman missed the entire season last year and SD missed him badly. Only time will tell if he will ever be back to his old Charger Bolting self.
Not all of the players hate it. The preseason has led too many careers that probably would not have been careers otherwise. Most recently the biggest undrafted stars who benefited from the preseason and earned spots on their teams are Antonio Gates, Willie Parker, and Tony Romo, all pro bowlers!
As a fan, I can only understand why the first two games are played. Teams need to find a rhythm and they cannot practice a game type atmosphere, I get that. Coaches need to find depth for their team and the diamond in the rough players as I mentioned above, I get that too. But having 4 games is too much and too dragged out and that's where the risk of injury is called into play.
It's a shame to see any player go down in any game let alone a game that really has no significant outcome. Hopefully, Roger Goodell's proposal of adding more regular season games and dropping one or two of the preseason ones will go through and we can all live a happy NFL life.