> In environments more suited to them, they learn just as fast as folks with a more traditional background. In these instances, the occupation was fine. The teacher needed to be swapped out.

You're assuming it's the teacher's fault. That will be true in some cases, but it may impossible to tell at the time. What will be true in others is that the person (like me) was far more motivated by work than academia, and university at the age of 18 wasn't appropriate.