[cbhl]

It doesn't; what I meant to say is that "just because you don't see slackers doesn't mean they're not there".

As for the courses and the professors' capabilities, there are a bunch of systemic issues there. One is that "number of students who fail out" is a metric that is used to measure program performance, so first year is usually full of courses that are review for like half a given cohort. Another is that one often gets tenure for research, not teaching ability, so some professors optimize accordingly.

For what it's worth, there are plenty of folks who will tell you that you should "slack off" on a degree and just start a startup instead.