[eitally]

Two reasons:

1. Large class sizes are only effective if the instructional method is rote memorization. Otherwise, the teacher ends of having all the same kinds of issues corporate managers have.

2. Teachers literally go through years of formal education on pedagogy and effective leadership. Most corporate managers adhere to the Dilbert Principle, where they had been a competent IC whose role grew too big for one person, so they were allowed to hire a helper... before they know it, they're managing a team, until they become too incompetent at the managing part.