Were we not speaking about intent? You were suggesting that the intent of a play should be towards getting a first down.
A well executed play ... even a running play on 2nd 10, has that very intent. It's absurd that you'd think that the coaches wouldn't intend that.
Opponents know that Air Force and Navy will run it pretty much every down ... does that stop them? When their teams are executing ... they can be tough to stop.
Also, even if the opponent anticipates that you're going to run it ... that is why historically the Iowa QB has so much responsibility and options at his disposal. An Iowa QB was typically given a host of plays or checks to make based upon what the D is presenting. When an Iowa QB was a noob ... the options would be made more simple (likely related more to hat-counting - thereby dictating which SIDE of the LOS the play would go). However, as the QB gains experience, there are more options ... thus, it was the responsibility of the QB to get the O into the "right play" based upon what the D was showing.
Consequently, Iowa's O had a mechanism in place to deal with the scenario that you describe. However, for there to be success ... the added complexity obviously adds more "moving parts" ... possibly adding more failure-modes. The QB needs to make the correct recognitions. The QB needs to have an understanding for how the opponents likes to disguise things. The whole offensive unit has to have good communication and make sure they're on the same page. On top of all that - the execution, of course, has to be there too.
There is a reason why Ferentz always talks about how the O always has "moving parts" as it relates to performance and execution (on O).
