I have many times heard people say, for example at events for a ham radio club I belong to, that if you are a teacher then it is because you couldn't, or wouldn't, make it in "the real world."

Pointing out that teachers are highly-trained professionals who are often quite skilled, and who are an important part of what it takes to make a better future, in my experience just does not register very much.

There is a huge difference between “not making it in the real world” and “starting your own business”. Not that I agree with the first sentiment either.