For me it's ok, I guess. I have graduated years ago and it's strictly for fun. But I wonder if it also creates a kind of artificial divide for those not able to attend a university but could have gotten good use of this kind of material by self study.
Edit, found this quote from him on an earlier discussion which summarizes it nicely:
> I'm honestly seriously torn about this. There is a serious tension between pedagogical needs of students in formal classrooms and the pedagogical needs of self-learners. I've chosen to aim for the former. Yes, I know it's a bummer.