Where is all this headed?
Industry took a giant step in this country when manufacturers figured out how to use the assembly line. Instead of highly trained artisans, only people with simple, easily learned skills were needed to create products. This meant the wages of easily-replaced workers could be driven down.
In the fifties and sixties, the food industry figured out how to take the model out of the factory and put it into a service industry. Again, the advantage was that instead of having to hire a chef (high level of training and expertise, hard to replace, and therefor expensive) fast food joints could hire, well, anybody with the most basic level of skills. They could be easily replaced and paid minimum wage (in fact, the job requirements are so low that fast food places can easily hire developmentally disabled workers and get paid to do it by the government).
As corporate reform forces try to move toward a privatized, for-profit education model, they face one hard reality: do a better job with your factory and you can bring in more money, but the revenue side of a school is almost impossible to change. Doing a better job doesn't increase revenue: a school doesn't take in more money for A students than for C students. And capacity is hard to budge.
So the major way to increase profit is to control costs. And the big problem with costs in schools is that you have to employ all these certified people with training and expertise. The solution? Change the system so that you can hire any shmoe off the street.
End the state requirement that teachers must have certification. Let anyone teach.
Create teacher-proof programs in a box, so that all the "teacher" has to do is open the box and read the materials (This is a double-win, because you can make money on the materials, too).
Do away with tenure and seniority, so that you can get rid of any teacher at any time for any reason.
Set your system up for churn. Let people stay in the job only if they settle for no real raises ever. Load up on TFA urchins who will teach a few years and get out.
Now you can drive costs down dramatically and create a school that is no more expensive to staff than a MacDonald's or a phone center.