While I agree with his perspective on classes, some departments are hostile to this.
When I was in grad school, I was required to take a ridiculous number of course credits to satisfy the requirements. Moreover, if you wanted to pass the qualifying exam, you had to know the material in some of those courses really well. The professors always complained that the requirements were too high and many of their students would lose 2-3 years just satisfying them. But ... professors are the ones who made those requirements to begin with!
When I was in grad school, I was required to take a ridiculous number of course credits to satisfy the requirements. Moreover, if you wanted to pass the qualifying exam, you had to know the material in some of those courses really well. The professors always complained that the requirements were too high and many of their students would lose 2-3 years just satisfying them. But ... professors are the ones who made those requirements to begin with!