Everyone on top can deny this as much as they want, but those of us who have been in this position know it is true. While defended to a point, my former AP was allowed to create working conditions that did only one thing, encouraged senior teachers to pack up and get out.
Mrs. J was one such teacher. She filed a grievance concerning her program and won She wanted a more even program with higher level classes. In the spirit of the contract she was given two high level classes, two bottom classes and a middle class. This program was much worse than the original so she won and lost at the same time. The AP also wanted to give her an AP calculus class to teach, a class he knew she wasn't qualified to teach because he knew she would work day and night to master the material and burn herself out. He didn't care about the kids he would be hurting. He only cared about trying to get her to leave.
Ms. K was reprimanded severely because the kids in her class broke a window shade on a day she was not in school. She was told that if she had trained them properly this would not have happened. Term after term, this experienced teacher was also given the lowest level kids to teach. She was told, in the spirit of rotation, the pre-calculus classes she had previously taught would be taught by someone else but the rotation only effected her, not the young person who got to teach them.
Mr. K was criticized for failing too many the second marking period even though his end results were the highest in the department.
And, while I don't consider myself the best teacher around, I know I was a good one and I know how to relate and handle difficult kids. Yet, every term my program grew worse and worse. Each term I was hit with classes I had never taught before. I was never permitted to teach a full sequence of Math B and never got to teach trigonometry although I asked every term, wanting the experience before I left. It was only a little back door maneuvering that allowed me to keep the AP calculus class my last year, a class I am sure would have been taken from me if I stayed. The AP who helped me keep it asked me, on the side, how I would handle the year coming up as she knew as well as I did something was in the works to get me to leave.
Maybe all schools and all administrators are not like the one described, but there are enough around to know senior, experienced teachers are not wanted. The city, with its severe budget crisis, will end up paying money for loans and then get rid of the people who hung around when they start earning too much and get smart enough to question policies.