A summary is about utility. They are definitely missing something but that doesn't mean what they are missing is useful to them at that time.
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.
You don't learn what to discard if you just have an AI do it for you.