Not so for BS in engineering. A PhD candidate in mechanical engineering at my alma mater wrote his dissertation on processes we had commercialized (internally) years earlier. I make more dough than the tenured professors I know here in Houston. I'm far better equipped to teach in my subject than the PhDs because while we're relatively equal in terms of mathematics and modeling, I've had to make it work in the real world as opposed to writing esoteric papers about it based on observation.
An example would be the how and why of switching pulse streams to a stepper motor at speeds above the base speed. And I'm a gear-head (mechanical engineer).
Engineering is a field where an advanced degree is not nearly as necessary to be a "professional".
But I'll bet that's not true of a BS or BA in Astronomy...or many other sciences, let alone Art History.