Agree with you there justasmallfire, in any company I think it's best to recruit people from a variety of backgrounds and skill sets.
You need well rounded people, and while one person's passion for the teaching of flying might make him a great instructor of the basic skills of flying, another instructor's ambition to fly an airbus may well inspire the younger students to work hard themselves and keep them coming back for more lessons.
For a flying school to do very well, you certainly need a variety of skills in your team, including a good salesman to convert trial lessons into students (really my biggest weakness as a flying instructor), you need a very good pilot to be able to demonstrate and teach the basic lessons, and you need the motivational inspiring people to keep moral up.
A lot of people have two of the three, very few have all of them, hence the need to recruit a mixture of people who want to instruct for life, and those who want to move on, but still have useful skills to pass on.
Having said that, I cannot stand the people who purely see it as a stepping stone, only want the hours in their book, and don't really care about the end product for the student. I have no time for those instructors, and there are too many of them out there.
In my airline there is a healthy mix of people who got in straight from training with minimum hours, people who worked on the ground in the airline before, and people from an instructing background. If nothing else, it gives us all plenty to talk about on long flights, diversity is always good.