Most people are quite familiar with the saying, “Those who can’t do, teach.” This statement suggests that people who have failed or would be failures in the world outside of academia end up as teachers.
The origins of this quote and various permutations of it are unclear. An early quote of similar meaning comes from George Bernard Shaw in "Maxims for Revolutionists" in Man and Superman (1903). The history of viewing the teaching profession with contempt or at the very least disregard may date back to the origins of the apple for the teacher custom.
In the Middle Ages, knowledge was viewed as God’s gift. Since it was God’s gift, it was seen as wrong to charge for it. As a result of this view, teachers at many institutions were not paid at all for their work. They had to rely on the gifts and charity of appreciative students.
Sometimes, a teacher was lucky to receive an apple so he’d have something to eat. It’s rather difficult to develop a mindset that a profession is pursued by people of high capability if that service is offered free of charge.
The value of the work being done as well as the education level required to perform that work is reflected in the salary, yet teachers are still relatively low-paid compared to other jobs with similar educational requirements. Additionally, teaching is one of the few professions that require a higher education, yet people commonly suggest those who take that career path are deficient in some fashion.
Being a teacher requires more than a standard Bachelors degree, but many people still view teaching as a profession for lazy or unskilled people. A favored chestnut among those who hold such views is the anecdotal story about the incompetence of teachers who teach topics related to professions in which they have never engaged.
For example, a business teacher who has never successfully run a business can’t possibly know real world business well enough to teach the topic effectively.
The attitude that a teacher must have worked in the profession that his students will eventually pursue is a reflection of ignorance of the point of education. There is a difference between receiving an education and attending vocational school. A vocational or technical school teaches specific skills that a student carries over to a job.
Education is about equipping students with a broad base of knowledge they can draw on to become successful in the occupations they pursue.
It is up to the student to digest the information he receives and find an application for it in his life, not for the teacher teach him each individual step. Considering that each company and job demands a customized set of skills, this is certainly a more reasonable approach. Even similar jobs may require different approaches at different types of businesses.
The sales tactics for selling computers requires a different approach than selling cars. Also, companies in the same industry often adopt their own approach. Marketing at Apple, where the focus is on design and limited numbers of models, would be a very different job than marketing at Dell, where the emphasis is on frequent sales, different equipment combinations, and low price.
Universities need only teach the fundamentals of each discipline and the companies can do the rest.
If you feel teachers don’t know what they’re talking about when it comes to the real world, then you’re missing the point of education. The point is not to memorize a sequence of steps to be regurgitated as needed at a future job. Teachers are there to help you learn how to be smart enough to figure out those steps on your own.