The model of public education is not primarily agrarian, although the needs of a predominately rural population may have influenced the calendar back in the beginning. It is not even predominately industrial, although the way factories were organized strongly influenced the organization of schooling.
The most salient model of public education is the model of the mind we inherited from the Age of Enlightenment.
Without further ado, I give you the animated illustration of an intriguing talk by Sir Ken Robinson.
Education reform is stuck in a rut because society has not confronted its most basic unexamined assumptions. I have often said we need a complete systematic overhaul. I was satisfied to mod the car, but no longer. Sir Ken goes further and says we need a new paradigm. He wants to throw the car out completely. Furthermore, he does not want to buy a new car. He wants to build something a completely different vehicle, perhaps one we have not imagined before.