Some truth in what you say.
I spent a long time in sales, in a professional field relating to healthcare and although I have an advanced degree, the skills required to be successful in sales and promoting services and products, has little to do with having an advanced degree.
Relating with people and understanding how others tick, is by far, the most important skill to be successful in any type of sales and having a strong motivation to succeed, is also important, but that motivation to succeed, won't get you far, if you don't have the skills to relate to people.
Being in healthcare, I have been around a whole bunch of folks with a very high level of education and extremely intelligent people, in their specific field. Most of these folks, couldn't relate enough to people, to sell water to someone stranded in the desert.