They simply have been outrecruited the past couple of years. Who's going to run the ball? Who's going to catch the ball? Who'll rush the passer? Who'll cover the receivers?
Colt McCoy is a good quarterback if you surround him with top talent. But he's not the sort of player that can turn poor talent into good talent. Vince Young could turn a bad team into a good team (at the college level) but McCoy is no Vince Young.