> We are concerned about untrained amateurs going directly into trying to solve very difficult global problems. They can then cause harm overall, by lowering the average quality of analysis or launching ill-considered projects due to a lack of experience or understanding. A PhD reduces the risk you’ll accidentally do this.
This point is operating off of a different fundamental paradigm than the comments here that are talking about opportunity cost. Opportunity cost is looking at personal benefit, while the above is looking at the effectiveness at solving hard, large-scale problems.
Obviously, money is important, but for many (often those who are fortunate enough to have reached a certain income level), it isn't the only thing or even the primary thing.
I don't have much insight into how true the point actually is, but I found it to be interesting.