- Due to the nature of MOOC, the assignments are largely either multiple-choice questions or programming assignments that merely asked students to fill in some blanks in some functions (there are a few exceptions of course). What a descent US university does really well is challenging students with tough yet insightful and inspiring assignments. That's how students learn deeply and retain the knowledge, at least for me. Merely listening to lectures and ticking off a few ABCDs hardly helps real learning.
- Lack of feedback. A university course assigns TAs, gives tutorials and office hours, grades assignments with detailed feedbacks, and it is so much easier to form study groups and have high bandwidth discussions. MOOCs try their best to offer such help, but they don't work as well or at least not as conveniently.
- Many courses are watered down. For instance, Andrew Ng's ML course on Coursera is far less rigorous than that (229? I forgot) offered in Stanford? The course is great for students to gain some intuition, but I'm not sure if it's good enough for one to build solid ML foundations.