You are confusing result and motivation. Sacerdote’s comment describes one of the intellectual skills that can be obtained from studying economics; why students choose to obtain that and other skills is a separate question.

Hint: many people study many disciplines in order to make money one day. Ask the future lawyers in the govy department, or the third of any class that it pre-med. This is not necessarily a bad thing.

I don’t buy it. The majority of Econ majors are in it to learn how to make money, money, money for themselves. Let’s not pretend there’s no reason Dartmouth has the most financially successful graduates in the nation.