Not every one who says "I want to be a teacher" is worthy of entering into the classroom.
One important role of college teacher training is providing an opportunity for teacher preparation professionals to detect candidate’s flaws in character, lack of work ethic, as well as inadequate understanding of the subject, inability to communicate with students or a desire to "game the system." You can detect a good teacher prep program by the fact that they weed out individuals who do not belong in the classroom, just as much as their producing teachers who are competent professionals.
Really "knowing" student teacher candidates takes several years of face-to-face interaction with students. It involves detecting bad attitudes and behaviors that are not going to appear on a criminal background check. It is not going to show up in reference letters selected by the candidate. Over nearly 30 years of preparing teachers, about one-third of my advisees who aspired to teaching did not complete that program. Some discovered they preferred another vocation or could not master the subject or were not bold communicators. But some were routed by my colleagues and I to other degrees or even washed from the program due to serious flaws that indicated they should never be in the classroom.
Teachers are role models to their students. They must meet a high standard. And that takes a few years of teacher-student interaction to judge.
Various schemes have been set up recently to admit folks into teaching by various alternate routes. These folks enter teaching on a fast track without opportunity for our observation. The results are already apparent. Whether it is transition to teaching, alternate route, or specific programs to send out-of-work aeronautic specialists into the classroom, superintendents can tell you the success rate of these other-route teachers. About one-third succeed. Another third hold down the job but are not inspiring or enthusiastic and wish they were elsewhere. And about one-third are terrible, sometimes quitting their first week in the classroom. The more the program is online, the less these problems are detected. But this attrition does not happen with teacher graduates who have been vetted.
Some regulations have already been relaxed so that unemployed scientists can enter the classroom as STEM teachers. But there is no big pool of such scientists outside of a few large Kansas cities. Our most serious shortage of teachers is in the rural districts and they have no credible supply of local folks expert in English and social studies and math and science and music.
So who are they going to call? Cousin Bubba? While there are school districts that will strive to screen applicants, the very problems they list about getting qualified teachers reflect that they do not have this pool of talent to draw from.
Schools assert that these pseudoteachers will have to maintain high scores on the student assessments. That is nearly unrelated to what good teachers do. Parents want teachers who help their child be honest, help students do more than what they thought could do, become a young lady or gentleman, develop excitement about academics and a future career. Parents are fed up with teaching-to-the-test.
Education schools do not catch all of the bad eggs, just as medical schools graduate some doctors who end up in prison for dealing drugs.
But teacher licensure provides the time and opportunity to screen out many—something that hiring Cousin Bubba does not.