A (then) senior I know at a top physics factory was taking General Relativity, Quantum Field Theory, and String Theory. Since he had already told me he had no intention of going on in physics, I asked: why those courses? His answer: "because those are supposed to be the hardest courses they teach here."
The answer makes more sense to me now than it did then. It's natural for young people to test themselves, and for a purely intellectual test, it's hard to beat physics. Top employers like to hire physics graduates of top schools not because it has taught them to think, but because success in a physics degree is evidence of high intelligence.