I taught advanced math in a Christian School and I had an answer, which I got to use one time:
“When are we ever gonna need this???”
“Oh,” sez I, “This is not for you. I have to put something in the course so my smart ones can really shine. It’s for them. I can see how you are not ever gonna be in a situation where you will need this, but they will.”
(Shocked silence. Then my mischievous smile. Their eyes rolled, and I went on with the lesson.)
Never heard that from anyone else ever again.
I was able to give them a way to succeed at it. When they could do it well, they knew that they had accomplished something truly meaningful, and the students who could do it did not need to know if or how they would need it.
For the same reason watching movies will make you a better bad banker.