I went to a top US university in a stem degree. My coworker was a med student that couldn't pass the Mcats, but wasn't a bozo. Basically everyone had a degree, and everyone made atleast $100k. I personally made about $225k but as I said, I was pretty good. I know a person in Bay area car sales making $300k+. I assume there are many others.
I assume you agree a McDonald's employee is not going to close accountants and doctors and lawyers and programmers on a car as often as an engineering grad would... And if that's true, why would a car dealership hire McDonald's type employees instead of slightly failed but still intelligent university stem grads? They don't cost more, since it's all pay for performance.