Why Freud is a Quack

According to my professor:

You bring 50 ten year-old boys into a room, and Freud says, "Okay. My theories say that they should all feel erotic desire for their mothers. For every one that admits that, I get a point. And for each boy who denies having such urges, I say he is experiencing repression. Score another point for me. Lookee, I score 50 points! I win!!"

A theory that claims to explain everything actually explains nothing at all.

All I can add is AMEN.