I have always found questions like "when are we going to use this" repulsive. It is the mark of an individual who sees themselves as little more than a slave, forced to learn things to stay useful.

The logical conclusion of this would be a world where everyone only knows exactly what is required of them and nothing more. Answering this question would miss the whole point. What ever happened to general knowledge? Don't you want to understand a fundamental part of how the universe in which you exist works?

If you don't know calculus I consider you illiterate and unable to understand much of world you live in, just like you are illiterate if you don't know that the earth is round (and why would you need to know that, I wonder?).