Well, as a teacher's daughter, I would say that parents and students play a BIG role in driving the good ones out of the system. I never even once thought about following in my parents' footsteps after seeing how the system demoralized them. I remember one incident in particular. My father taught high school earth science and for the section on mining he brought in some photos he took on one of our family vacations where we visited the open pit iron mines in Minnesota. A couple of these pictures showed us kids next to one of the monster mining trucks to show size. SOMEONE complained and said Dad was using class time to show "home movies". That was the LAST time Dad ever went out of his way to bring a little extra to the class. From that time on until retirement he taught strictly from the book and only from the book.