It’s a good question.
Should professors demand more? And will doing so make students learn more?
One take from The Chronicle of Higher Ed:
The study makes clear that there are two kinds of college students in America. A minority of them start with a good high-school education and attend colleges that challenge them with hard work. They learn some things worth knowing. The rest—most college students—start underprepared, and go to colleges that ask little of them and provide little in return. Their learning gains are minimal or nonexistent. Among them, those with a reasonable facility for getting out of bed in the morning and navigating a bureaucracy receive a credential that falsely certifies learning. Others don’t get even that.