When looking at organizations, both businesses and charitable places, I’m always amazed why people stay on, even when it’s time to go. I was a part of a Hebrew school where the PTA President no longer had kids in schools. Same with the current school board where I live. I don’t think I’d mind these things if they were doing their job, but it hurts when they aren’t.
I have been very lucky in life, I know from jobs and other organizations, when it was time to go. Whether you have accomplished what you have done or things aren’t going the way you want, it’s important to recognize when you should be leaving. Give someone else a shot.