Browsing EA Sports own forums, one of their developers shed some actual HONESTY. He said the reason Madden doesn't have true coach mode is because their engine isn't designed for CPU vs CPU game play. Now let us all think hard about this for a few minutes. Let it marinate.
If the CPU can't perform against it's own self in a game, then it REALLY isn't designed for Human vs CPU game play either. So why don't EA Sports just come out and say hey, our sports game is really designed for user vs user game play.
Our games really don't think for itself. Instead it just reacts to YOUR button presses and your stick presses. If they did that, people expectations playing against the CPU would be much lower.