The major missing component of MOOCs is intensive homework problems that often requires you to consult professors in their office hours. And the time professors/TA spend in checking your homework.

The core thing to understand is that real learning doesn't happen when you are listening to lectures but it happens when you are working on homework and doing exercises where you struggle through and occasionally have to go back to professor's offices to get insight.

But the truth is that the price of education is mostly justified as "certification service". When you have degree from Stanford it means someone very reputable is backing up your claim that you have learned thing or two about something. That's mainly what you are paying as "tuition fees". MOOCs are relatively much weaker as certification services and hence chances of them getting trusted is same as chances of trusting degrees from many other "online universities".