Erin clearly feels that the educational system sets up kids from certain backgrounds to fail. The system is all too quick to pigeon-hole students according to their race and the neighborhoods in which they live, deeming them "unteachable" as a consequence. As Erin soon discovers, this short-sighted approach simply exacerbates the problem, creating a vicious circle of educational underachievement.
As these students have been deemed unteachable, they're denied a decent education; as they're denied a decent education, it becomes even harder for teachers to reach them, compounding the problem rather than solving it. The poverty of low-expectations has kept these students in a state of ignorance, denying them the chance to break free from the seemingly endless cycle of deprivation which they endure on a daily basis. Erin knows this simply isn't good enough and that a whole new approach to teaching is essential if these kids are to be raised to their full potential.