No school system could be asked to assume 100 percent responsibility for overcoming the burden of demographics. The rules of demographics have not been repealed in the decades since then. Deep down, most of us know it's more complicated than that. When a child passes through 12 years of school unable to absorb what she is being taught, much of the fault has to lie somewhere outside the system. Parents have a lot to do with it.
Peers are part of it.
The whole popular culture is part of it. All I would ask is that if we wish to apportion responsibility fairly on this issue, we try not to leave the individual students out altogether. What's true of education is equally true of poverty and welfare issues. So many of the professionals who work in these fields have ceased to talk about the disadvantaged as independent moral beings with wills and responsibilities of their own. Instead of subjects, the poor become objects.