I mean I think that points to a related issue of people only focusing on a short-term notion of utility. The point of being a student is largely to learn things that may potentially be of utility to you in some way later, not just to do what meet your immediate needs (in the sense of passing the class).
I get what you're saying and I myself am guilty of surface level learning. But the idea that students should consume all the information is impractical. Learning what is acceptable to discard is part of being a student. I imagine very few students read every college text book cover to cover.
Beyond that people have different motivations and goals and only a limited time to achieve them. Basically I wouldn't be so quick to judge. Plenty of students have dropped out and gone on to do impressive things and that's a bit beyond reading only the abstract for a few assignments.
