And yet, where do you get that experience if everyone requires a type rating? Kind of a catch 22. That's why you need the lower levels of aviation, to give the newbie some experience, and force him to use what he's learned and make smart decisions with minimal co-lateral damage when he screws up. Training is great, there is certainly a lot of knowledge required for airline flying, regardless of whether that knowledge is acquired during private pilot training or during airline indoc. But eventually you have to get kicked out of the nest and fly.