And look at what that economist is saying; is any of it insightful or something that a person with a basic knowledge of human behavior and logical reasoning could come up with, if they didn't know already intuitively?
They do it to give a sheen of authority to arguments or really assertions of opinion. Murray Rothbard called them court intellectuals, whose job is ultimately to run interference for the regime. Basically, they are the ones telling everyone, "but I can see the emperor's clothes very clearly and I went to school for a decade."