It's certainly true that the presence of a stable, supportive, and expectant family plays a critical role in a kid's success in school.
That said, from a teacher's point of view, you are dealt whatever hand you're dealt. And you're going to have to play that hand. Once a set of students arrives in your class, the arguments and debates about home life, or "background", aren't going to do anybody any good. So, while background may be the most critical factor in a kid's success (I would say that it probably is), educators are still left with the task of doing the best they can, instructionally, with whatever set of backgrounds walk into the room. Saying that kids come from a crappy background doesn't obviate the need to think about our methodological or operational assumptions. For even though background might be the most important factor, it is not a factor that is easy for us to get at; and if we can get at the second-most important factor more easily, then it seems sensible to do so. Or, to my way of thinking, if the chaos of the "background" is beyond our control, then it makes it even more important that we avoid adopting instructional or operational models that do not work.
The current operational model asserts that the administrator is the instructional leader. It's a phrase that teachers hear a lot: "administrator as instructional leader". For instance, on a recent staff survey that was conducted prior to the hiring of a new superintendent in my district, there were several questions asking about the importance of the "superintendent as the instructional leader of the district", or, more specifically, what sort of instructional leadership we wanted our new superintendent to demonstrate. We hear it a lot, but I'm not sure anyone has really ever vetted the assumptions that underlie that model. Like all other things in education, the experts will cite research pointing to the importance of having "an administrator as instructional leader", but the research hasn't been vetted either. It's simply passed along as a fact, and it is used to justify top-down, universalistic, one-size-fits-all approaches to instruction. After all, if the administrator is the instructional leader, then he (or she) has the job of laying down instructional rules that others are meant to follow.
The problem is that administrators are not instructional leaders. There is no body of knowledge that administrators receive by virtue of their training that teachers have not also been given by virtue of their training. Administrative trainees have focused, to a degree, on theoretical approaches to learning, but documenting the validity of those theories (mostly constructivist theories) remains an elusive task. Certainly there is nothing that rises to the level of what we could call a "methodological knowledge"—nothing that deserves to uproot and discard the practical experience of effective and conscientious teachers.
The "administrator as instructional leader" operational model has had the effect of reversing the natural lines of authority—in which the content is the master of the teacher, who is then the master of the student—in favor of a command and control mechanism, whose business is quality control and the elimination of variety. Content and relationships are subordinated to data analysis and "guaranteed, viable curriculums".
It's my sense that this sort of institutional drift is at the heart of the public school crisis that we now face. "Background" is a key piece of the puzzle, to be sure; but along with that is the continued erosion of the authority of the teacher in favor of the authority of quality control mechanisms—the search for the El Dorado of accountability. The drift is a result of many different sentimentalities and the quixotic responses they have provoked, responses which bleed together in unpredictable, confusing, and sometimes indecipherable ways. This is the source of our frustration as teachers, even if we can only articulate it in fragmented, and often contradictory ways.