A fascinating article Elizabeth!
I am not taking my classes "for a degree" - I don't need a degree in my line of work. It won't get me any benefit. However, I am taking the classes for a structured learning experience with fellow students who are in my line of work.
That is, I already have tons of books on management. I've read them all on my own. I get no feedback that way though. I don't know if I'm gaining the full knowledge. With an experienced mentor to guide me (the teacher) and an experienced set of business leaders to talk with (my fellow students) I get a far more rich experience. Also having the structure helps ensure I move through the material and learn it thoroughly. I love the feedback I get both from the teacher and my fellow students. The classroom discussion with experienced managers is by itself worth the 'admission price'.
So I would not enjoy an open course with 16000 students in the class. To me that would be pretty much like reading a book on my own. I can't imagine having a sane discussion in a forum with 16,000 students in it