Few things matter as much to teachers as being considered professionals.
When you are a professional, people assume you know what you are doing, and they tend to go along with your judgment in your area of expertise. But while doctors, lawyers, and architects won this acceptance many years ago, teachers are still fighting to gain it. One problem is that some teachers have not been ready to go along with the kind of rigorous standards that govern the entrance to other professions. Some have even fought against minimum-competency tests for prospective teachers. Some people who have failed the exam, and groups that support them, are challenging the test in court.