Who or what would you say bares the brunt of the responsibility for this?
Parents
Government
Teachers
Yes I know, all three, but which one is top of the list
The problem is that, because of the influence of the Frankfurt School on every institution in the United States, the school were gradually straitjacketed in their ability to create environments appropriate for teaching and learning. All methods which tended to distinguish between the highly intelligent/diligent on the one hand, and the stupid and slacker on the other, were increasingly eliminated. This was because the outcome was deemed racist, due to patterns that would naturally emerge. Discipline, also, had to go, because that would naturally also result in patterns along racial lines, which the left would characterize as due to racism, rather than being due to natural differences connected to race. And now little if any teaching can actually take place, apart from the advanced tracks that tend to be racially uniform. I'm certain, however, that advanced tracks, too, will soon be eliminated for the same reasons.