Don't blame the kids, blame the horrible public schools. The source for this article is a public school teacher in Oakland, a school district infamous for attempting to consider "Ebonics" as a language.
What if both parents work? What if everywhere else they can afford to live has public schools just as bad?
I suspect well off neighborhoods would still in general have 'better' schools, simply due to having more resources, but even the poorest of parents would have at least some competitively exposed, hence at least decent, options. If nothing else, charity, churches and such would help out the neediest of kids.
As it stands now, a poor parent in an inner city (even more so in one as much at war with religious anything at all as Oakland), is pretty much left without viable alternatives to the local public indoctrination institutions.