Most people don't know how light bulbs work because it doesn't matter how light bulbs work. They can't use that knowledge in their daily lives, so it really doesn't matter how difficult it is to acquire that data - as long as it's difficult enough, it's not worthwhile to expend the effort.

Being a physicist doesn't give you any nifty powers, and the phenomena they have the knowledge to predict don't affect the everyday lives of human beings on a perceptible level.

Most people weren't clamoring to learn the Pythagorean secrets, either.