For instance, if I was getting spinal surgery, I wouldn't want the guy that only got 70% of the maximum benefit from med school (if you could measure that). Still, there are lots of professions that do not involve life and death situations and programming is one where you can generally screw up a few times when you get started, provided you're not building life support software. Everyone has to start somewhere.
Re: not understanding--you're right, when I said "I really don't get why", I didn't mean that I really don't get why, I just meant that it disappoints me that apparently rational, educated individuals would come out against a general push towards free, massively delivered education for the world because it's not a perfect alternative to a massively expensive entrenched alternative.
It doesn't surprise me that most people don't recognize this. Most people haven't actually thought through the nature of what they seek to replace. They've grown up on broken education--content delivery--so they think that broken education's problem is simply one of scaling the delivery system. They've grown up in a country where education is a minimal priority financially, so they think that the solution to its problems is economic.
Those of us who have been fighting for education reform since before Salman Khan are watching this and seeing the opportunities we worked so hard to wedge open slip away. Instead of breaking the classroom-as-church-sermon paradigm, MOOCs have enforced it with an iron fist. Instead of creating legitimate ways of evaluating student progress, MOOCs have doubled down on the worst methods of doing so. Instead of helping us recognize that education is not just a funnel for the job market, MOOCs have emphasized it as its only real purpose. This is anti-reform. It's like saying you're fixing Big Brother by installing more cameras and wiretaps.
Does it have a benefit? Absolutely. A lot of the technologies and methods being developed by MOOCs are things we could use if we actually had real reform. Khan is trying, in his own way, to do that; that's why he's working on a brick-and-mortar school.
It also has an interesting risk. The liberal arts of universities have been a refuge for political dissidents in developed, educated countries. They provide a decent level of security from which loud criticisms can be made. Arguably, the blogosphere has obsoleted such agitators, but what if it hasn't? How do we account for this in an age of MOOCs?