The question is reasonable

"Why am I learning this" gets treated as insubordination, and it is a fair question asked in good faith by people being asked to spend years and a great deal of money. Answering it badly — you will need it later, it builds character — is what produces students who comply without believing any of it.

The honest answer starts by conceding the point. Much of what you are taught you will not use directly. That is true, everybody teaching it knows it is true, and the case for education has to survive the admission rather than dodge it.