It's a sales problem. "Why should I care about this in the first place?" It doesn't necessarily have to be for something, but if you can't communicate any value, then... yeah... the results speak for themselves.
One of my favorite thing about getting older is finally learning answers to questions I was asking high school teachers. (e.g. applications in math class... though to be fair, I had the same problem in undergrad too!)
Most such things I ever grew to appreciate, happened from some sort of example case that doinged me on the head, and then I recognized how the principle applied elsewhere. Then the understanding of the principle itself was just part of my understanding of life and the world after that.
It would seem that the job of a teacher is to understand this themselves, having once been a child themselves or at least having had experience with kids in their own training even if they themselves were a different kind of kid, and to actively construct scenarios that teach concepts to kids who are not already aware of them or believe when things are simply stated at them.
Simply telling a kid something is approximately useless. If you want them to understand it, you have to understand them, and arrange for them to walk through some process where they end up arriving at the understanding "on their own".
I'm sure it's not easy but my own job is not easy either, but that just means it's a job that has to be done and doesn't just do itself, not that it's not doable.
One of my favorite thing about getting older is finally learning answers to questions I was asking high school teachers. (e.g. applications in math class... though to be fair, I had the same problem in undergrad too!)