Snake oil salespeople jumped into moocs and have pushed their ascendancy back by years. They, presently-generally work great for a specific set of people, but don't yield sufficiently effective results for broad groups. Check out the research thus far. It's not as engaging and lacks the habit-forming that drives people to complete and compete for high marks in areas which aren't in alignment with the interests of the student.

For mature learners focusing on a topic of interest, great. For young learners build a general foundation, not so much. Now, it's a different conversation to cover curriculum, but that's not of MOOC's concern.

And, to wit, "adults not recollecting fond experiences" is double-edged. There are few other times in people's lives where they are essentially forced to rub shoulders with such a cross-section of their culture. These experiences do afford experience in cross-pollination which have positive benefits as much as they cause angst for participants. If parents are able to shield their kids from "others" a certain solipsism is a consequence. During formative years, there is a value to broad cultural experience that should be balanced with providing a safe and nurturing environment for the primary task of learning.