alt Hacker NewsAt Caltech, the usual was to double major with one to make money, the other for fun. The fun one was usually Astronomy, where it was well known there were no prospects for employment.
In my case the problem was there were too many fascinating engineering classes to take. I tried to pick out ones that would be of maximum benefit to my chosen career.
Tbf, Caltech is also a much more self selecting student base.
Plenty of my MIT friends explicitly chose MIT over Caltech because they wanted a technical education but also the freedom to deep dive in English or Political Science as well (Caltech has great faculty in the HSS, but class choice was unsurprisingly limited).
That said, based on your account age, I think you studied in the 1980s to early 2000s back when programs were much less interdisciplinary. It's much easier to double major with a STEM and humanities major from the 2010s to present versus before.