In the 1700s and 1800s, bold adventurers sailed around the world in what were then called ships but what would, by today's standards, be considered little more than small wooden boats.
Many of these men accumulated vast wealth, buying and selling spices, teas, coffee and other in demand commodities. In spite of this wealth, these traders were not accepted into European society. The reason for this was simple. In the high society of the day, it did not matter how much wealth one possessed. What mattered was whether or not one had to actually do something (i.e. work) to acquire their wealth.
We have managed to recreate this concept, one which the founders soundly rejected. We have always differentiated between professions, in which one wears a suit and works at a desk, and trades in which the accepted attire is a T-shirt and jeans and the work actually makes one sweat. Sweating itself in not considered a bad thing as long as the sweating is the result of some form of working out, preferably in an air-conditioned gym.
Of course, our high society is unlike that of pre-industrial revolution Europe in that the only requirement for admission is wealth. Any boor can join if he's rich enough. But the idea that one must have a degree to be an intelligent person and that working in the trades is a less than desirable fate has become embedded in our culture.