Imagine you are looking at colleges with your child. You come across one with a Department of Astrology / Astronomy. Curious, you go talk to one of the professors of Astrology / Astronomy. He got practically lost in stars, galaxies, nebulae, solar wind, the missing dark matter, etc. Fine enough, but then he started to tell you what the stars told you about yourself, your family, and your future.
You would probably back away down the hallway, and not be able to leave the campus soon enough.
Now imagine an economics department staffed with economics PhDs. Unfortunately for you, you aren't forewarned that some of the professors were cranks: labor economists, historical economists, and their ilk. You start talking to one about investment and productivity. He talks about interest and gains to labor because of investment. But then he starts to condemn speculation, and you know that this is the wrong college for your child.
This is the state of the art in economics today. Some of the people are simply cranks. Some of what they know is correct, and some of what they know is flamingly incorrect. They don't know the difference, and worse, their students won't know the difference either.