You've just illustrated some of what the author was writing about. Your judgments about these students' home life is not completely coherent. You put in time helping a kid with projects "after a full day at work"? Great. Now try it after a full day of work plus a night job. Oh, and how is that kid going to perform in school if you had to wake him up at 1am to give that help? And if you, yourself, never took algebra, exactly how are you going to help him with algebra?
I'm all for people preparing themselves as best they can to parent and then giving it 100% effort. But I cannot get behind a vision that limits parenthood to people with "good" jobs, middle-class salaries, and great educations themselves. Compensating for such deficiencies IS, in fact, why we have public schools and don't leave education to private tutors paid by families who can afford them.