re: Old Money v. New Money: Why is Old Money preferred?

It's behavioral, obviously.

The idea is that old money guys may drive around in a 1990s Mercedes, be polite to people, and decline to flash wealth all of the time. That's not always the case, but that's the example that will be held up.

Whereas new money will have a flashy sports car, act like a douche to everyone, and let everyone know about their new wealth. Of course, that's not always the case either.

In the South especially, old money is often a term that refers more to social status than wealth. Old money frequently means no money, as the sources of wealth have often dried up in a changing economy, and/or have been used up by family leeches.