Nah, the problem is trying to make Favre happy by throwing the ball. Minny has a solid O-Line, but Favre is about himself right now with calling off running plays.
They lost games because they weren't having Favre throw the ball. Childress himself finally realized that when Favre isn't being Favre, defenses just sat in the box and whooped on AP.
Up until the Arizona game, and from the second half of the Bears game it was Favre first, run second, and the offense was world's more potent than when they were trying the balance for the sake of balance stuff.
The NFL is a pass first league now. Three yards and a cloud of dust died with Woody Hayes. If the Vikings come out trying to run the ball on 1st down everytime they have zero chance of winning the game, and they realize this because they lost the games this season in which they played the game plan you are advocating.
For what it is worth, the locker room was apparently 100% behind Brett Favre over Childress in terms of whether or not Favre should be over ruling play calls at the line. They saw like everyone else that a conservative game plan is a loser for them.