They told me that when you're on your own, you have to figure everything out yourself. Sure, you can email your teacher a question, but you've got to wait to get a response and then maybe it's not clear and you have to ask again, etc. Conversely, most questions can be explained/handled in person in a fraction of the time.
I cannot argue with this as I have had experiences where I wish I could speak to the teacher outside the class beyond e-mail and the phone too. I guess in my experience though since the teacher was being broadcasted live over satellite it was easier. Those classes had two way communications which allowed us to talk to the teacher via a microphone during class. If we missed class, we could get the video tape of the class we missed (since all classes were taped). Some teachers did a role call of all the students (as well of all the satelite students) to ensure that students would not skip class during class time and only watch the tapes later. Most professors, however, did not care so long as the student did the work and mastered the class.
The third ad in this series kind of describes what we had. And it was not brought to us by AT&T.