I never said engineers earn more money or suggested the son become an engineer. If he thinks he might like business more, that is a perfectly fine option. Double majoring in 15 and engineering gives him the best chance to be successful. Let’s work this out backwards. If he chooses business, he should get an MBA. When he applies to MBA programs, the admissions committee wants to see that the applicant will make good use of the degree, meaning he will earn a lot of money. Who is more likely to earn a higher salary? An MIT grad who majored in business or an MIT grad who majored in an engineering field? Probably the latter. If that undergrad degree in engineering helps him get into H, U Chicago, U Penn, or S Business instead of a second tier, he is way better off. With an MBA in hand, who has a better chance of being hired at Apple or Google? A Harvard MBA/MIT undergrad who only knows business or a Harvard MBA/MIT undergrad who majored in Course 6 or 2 or 10 or 3? MBA degree has more value to someone who has industry expertise. There is nothing to debate here.
Going back to the original post about respect on campus. MIT students value intelligence. There is closet studying because saying you pulled an all-nighter and got a B isn’t as impressive as saying you studied a bit and got a B. So, students in Course 4, 15, and 21 get less respect. Perhaps everyone is too polite to say it publicly, but it is what it is. I once worked with an MD who told me he went to MIT. I was impressed until he told me he was Course 21. It’s possible he really loved humanities. It’s more likely he didn’t do well in science and math.