I have had 'students' who clearly had no business being in a college classroom and should have been out in the 'real world' doing something useful like driving a truck. Dennis Mangan sounds this theme, and links to an interesting post. I have an extended rumination on this topic elsewhere.
Mangan, whom I read regularly, seems to differ with me on the value of higher education. If I am not mistaken, he views its value, or lack thereof, primarily in economic terms. To me, that is secondary, the life of the mind being primary. But then I am the sort of romantic and idealist who drew inspiration from books like Gilbert Highet's The Art of Teaching and Cardinal Newman's The Idea of the University. Now that I think of it, the fact that I did find those works inspiring is part of the reason why I no longer teach. The discrepancy between the ideal and the real became unacceptable to me.
Such books don't speak to the current reality. On the other hand, the very fact that higher education has become a mass consumption item is part of the explanation of how someone like me could have gotten a teaching post in the first place. It's a complicated situation. The widespread availability of educational opportunities is a value, both for students and teachers, but one in competition with the value of high standards.