>who knows what and in what order to teach.
Plenty of courses have their general outline publicly available. Some colleges even share older lectures [0]. There are more-than-enough resources available for self-directed learning. Have questions? StackOverflow exists.
The #1 criticism against self-directed learning is how self-motivated the autodidact is. Most people suck at staying motivated to teach themselves. If they aren't 100% passionate about learning the subject and can keep their interest going, they will fail.