Some people need vision for motivation to succeed. Kids who ask the above question are almost always that breed.
For example, I discovered years later that Algebra is useful for developing the ability to think logically from an abstract perspective, enabling the thinker to be detached from the content and thus more objective with his or her thought progression. This discipline develops higher thinking skills. If I had known that 10 years ago, I might have tried harder.
But wait... Then I would have passed Algebra II the first time and I wouldn't have needed Allie to help me pass it the second go 'round and then I wouldn't have started dating her, so we wouldn't have gotten married, and we wouldn't have Cecily...
On second thought teachers, keep enabling mediocrity by forced academic servitude without educational vision. That worked out for me.
(As a side note, the above "change of heart" was a functional illustration of how reason can suffer when personal investment muddies the components of the argument, eg. I'd rather be married now than academically successful years ago, so I'll settle for a flawed argument that supports my favored outcome.)
Yay for Algebra, and yayer for knowing what its value is.