One issue with the chain of logic: The value proposition of school is NOT the lectures. It's other things:

1. Good teachers who can individualize instruction (software cannot do this yet, even state of the art like Knewton is rudimentary compared to a good teacher)
2. Signaling (Everyone knows that if you learned at harvard you've already been preselected, nobody knows this about random person watching a video online)

I agree in large part with what you said, but the two issues above need to be solved.