rebuttal?

[crs]

I'm looking for an informed, even-handed rebuttal of this paragraph: There are countless dedicated public school teachers in our nation. Guggenheim made a doc in 1999 focusing on them. But educators and the teachers themselves acknowledge that schools have teachers who are not merely incompetent, but even refuse to teach. Protected by the tenure guarantees in their union contracts, they cannot be fired. In some schools, their rooms are referred to as Classrooms of Death. A student assigned to them will fail. Principals know this, and every year engage in something variously known as the Lemon Dance or the Turkey Trot, transferring bad teachers to other schools, and praying that the new teachers they get may be better.
from this Roger Ebert article: A Superwoman for Kenya, but America is Still Waiting for Superman. Anyone?