I don't know, this doesn't match my experience. I've been multiple places were the teachers in high-mobility fields were bad because anyone good at them could

I don't know, this doesn't match my experience. I've been multiple places were the teachers in high-mobility fields were bad because anyone good at them could move up easily. takes just one bad interaction with a superior or nagging from a spouse and poof. This doesn't apply to people who love teaching, they're in it for different motivations.