I agree with MR25 to a large extent for sure, but it's one of those things where I don't know a good answer to solving that problem. Like you said, paying attention in school and doing well is not only not popular in inner cities, but kids are often beat up/tormented/intimidated for daring to actually give a sht in school. I've heard countless horror stories from teachers in urban schools who have said repeatedly that money is not the problem, it's cultural. One anecdote that comes to mind involved a whole host of kids just chucking their school-issued laptops down the stairs over and over again because it was funny.
Just like any other major cultural change, you have to get them while they're young. But with how awful so many of the parents are, even if you theoretically provide "equal opportunity", I'm admittedly skeptical much will change. A butt-ton of money is sunk into inner-city schools every year but if there is no will on the part of the students, what can you do? No child is born "bad".
I agree that parenting would help, but I think your point is ignoring that the parents (and their parents, and their parents and...) were all part of this system of lack of opportunities and education, and the cycle has just been on repeat because it's obvious nothing is being done to change it (you can point to more money in schools, but it's the utilization of those funds that truly matters, not how much).
All these issues stem from the systemic lack of opportunity.