We had an engineer at work who had two PhDs. All the other engineers called him "Doctor, Doctor". Among a workforce of about 800 nerds (mathematicians, physicists, engineers, etc) he was the most difficult and unhelpful person to work with and, because of this, generally got shunted off onto meaningless projects. My brother-in-law was working on his PhD in mathematics (at U. Chicago) and doing a little side work for the business department. A business professor had a little talk with him and said, "You know that with a PhD in math, you'll be basically unemployable. Math PhDs have a reputation of being very strange people and no one wants to hire them." Shortly after that he transferred to the business department and got his PhD from them.