...some of that (on defense, at least) has to do with injuries and a lack of depth/players. If the players you've got on the field have weaknesses you're trying to cover to keep from giving up big gains to the other team, it might be risky to be as aggressive as you'd like to be.

That said - it's not like they should be afraid that taking risks will lose them the game. I say it's time to just let everything hang out and go for it.