[mgenzel]

Because highly successful people are not necessarily those who can teach (and also, are 'human teachers' anyway). Teaching is inspiration, empathy, enthusiasm, wit, patience. You could be a Nobel Prize laureate and have none of these, and you'd make a perfect snooze-worthy drone (witness some highly decorated profs at some top universities). I'm going to assume you don't have any children because I think otherwise you would see how much a difference person's personality has on the child's ability to learn.

Granted, many teachers suck. In the U.S. we don't have a system that rewards good teaching.

Also granted, the ability of the current technology to bring amazing (human!) teachers to the masses is great and growing. But, teaching is a two-way street, and you can't have much of that with 1 to 1 million ratio.