Because thanks to the Bush recession they laid off tens of 1000s of teachers and no one will change school districts right now. Maybe she could have left before but waited too long. Then again maybe she'd very dedicated.
YES there are poor systems... they are that way primarily because of lack of funding to meet their needs
(> average). Sure there are "bad teachers" but there aren't that many %-age wise, & they don't kill the whole system. I always ask a friend of mine who constantly whines about education... "Could you take Normandy Beach with 1 brigade ?"
Try teaching in a classroom. IF someone hasn't been there then, they don't know WTF they're talking about !! I WAS there in 1974, and it was tough... it's even harder now !!! much harder !
Teachers should be treated like our military vets. . . with great respect and support.