(As always, my world is front-end web development. These are observations made after watching conference speakers and attending workshops in my field.)
The motivation for teaching is often to get attention or get famous, show off their personal skills, gain fortune, or to try to be an early dominator in some obscure technology or another.
Notice how not one of those reasons is to help other people.
In other words, these prospective teachers want to be the hero, not a guide.
A hero is Batman. A guide is Alfred.
Where would Batman be without Alfred? Luke without Yoda? Cinderella without her fairy godmother?
The hero is the student. The student is slaying the demon of ignorance.
Your role is to help them by providing them the sword. They will take the skills you teach and wield them on a chaotic universe.