Few NFL athletes are as muscular and cut? You must be talking about the Detroit Lions or something cuz the rest of the backs (RB, FB, DB, LB, WR) are for the most part muscular and cut. They have to be. With all the conditioning on and off season it's tough not to be. Of course you have your Jerome Bettis's too. I'm not saying that everyone is as cut as Shannon Sharpe or Curtis Martin, but they look good.
Just a side note, although Joey Galloway isn't huge, that bitch is strong as a MF! Most of his strength is in his legs though.