Exactly. It’s possible that no teachers could be “highly effective” with this population, although the results of private and charter schools strongly suggest otherwise.
Based on personal experience, these are probably the students that private and charter schools (rightly) reject. The students don’t care, nor do the parents. I teach in a small, urban public high school. I’m teaching third generation welfare recipients. Their grandmas and moms have lived on our bounty, and they know that they will also. Why study or try to do well? Why go to a private or charter school that’s just going to kick you out?
At the same time, in Ohio we have a new teacher evaluation system. It’s a joke. It’s too much trouble for the school system to deal with an ineffective teacher, so they just get ranked artificially high. Sigh.