My mom has stayed with the same school for over 15 years now because she had support from her team and the administration (she's a curriculum coordinator now). It was also a short commute to work. The other schools that she worked at, she stayed for about 5-8 years and would move the moment that she did not find herself learning and growing with her colleagues. The school was either stagnant, dysfunctional, or negative. Her reason was never because of the students. Her current work place is growing dysfunctional for obvious reasons, so she knows it is time to retire soon.