As much as we all love to watch it, the fact of the matter is, that if you don't love to play it, it isn't any fun. In fact far from it. So no matter how talented you are, you can't come close to maxing your potential if you aren't willing to commit to the game 100%. And to be able to commit to it 100%, you have to love the game. You have to love the competition, the practices, the study, the preparation it takes to get your body ready to handle the physicality of the game for up to 19 times a season.
That is why BB feels its so important that his players love the game, and that its important to them. I know it seem corny, and passe when its mentioned, but McClain's retirement is a good example of what happens when a football player at that level don't like what he's doing.