In the MSC you have multiple instructors available to you whenever you need help with the software, finding a resource for studying, answering a question on a homework problem, reviewing a quiz, preparing for a test, etc.
The course would not be able to be individualized, nor allow students to start in a variety of Units based on Diagnostic scores, and still be offered in a traditional classroom lecture mode. The benefits of being able to work at your own pace, and skip Units you have already mastered, outweigh the convenience of having a scheduled set of lectures for the course.
There are lectures available in the course software and on a variety of external sites. [And, CWI will be creating a library of video lectures based on student feedback on particular instructor's explanations that are helpful.]