Ok, so what is your suggestion for making the parents less poor or less high? General and baseless comments like these do not contribute positively to the collective conversation.

Choose another metric to compare schools/teachers (next to impossible), or factor in the "poorness" of the students/their parents. E.g. a rich, clean white hood gets higher thresholds for A than a poor black hood filled with junkies and violence.

This is not perfect either, but a rich/poor offset allows for a far better comparison.