I spent a few hours per week last semester at a low income, almost totally white, elementary school. It was an eye opener! Getting ANY cooperation from those parents was like pulling teeth.
Kids would turn up with notes that said that so-and-so was absent because "I had things to do" or it was too cold. A number of kids almost never turned in homework. When free, after school, tutoring was offered and recommended by the teacher, it was often turned down. And you know these kids weren't going to Sylvan...
It's a mindset, an attitude. The teachers get frustrated and don't expect that they can do anything to influence the parents. I don't know who can.
For a large percentage of poor people, it's not that they have bad attitudes because they're poor -- they're poor BECAUSE they have bad attitudes