I've followed your articles on the teacher shortage with interest. One point that you have missed is that the education system does not want new teachers. It wants clones.
The system has much to lose if students are taught to think critically. The current simulation of education cannot stand up to criticism. According to current practices, prospective teachers must be broken of independent thinking, just as students must be dominated, so the old hands at the shell game can continue to rack up their fat salaries and pensions, undisturbed by the idea that learning should be taking place in the schools.
One of the most effective ways to replicate teacher-clones is through nepotism. Imperial County schools are rife with nepotism.
Calexico Unified School District is an example of an organization that appears to be a school district but actually is a job mill for members of prominent families, as well as a college-entry scam for the children of those same families. Kids from the right families can get into good colleges whether they can read or not — this is the purpose of the highly discriminatory Advanced Placement scam. Kids from poor or socially marginal families can count on going to continuation school, independent studies or other covers for getting kicked out as undesirable.