Answering “How is this useful to me?”
The grown-up answer: Because it's good for you.

No, really.    

At this age the different things you study all give you different kinds of skills and different ways of thinking. Thinking is good and the more different ways you can do that the more likely it is that you will be able to solve the problems as they come along. The different subjects in the early years are put there because people (grown ups) think that they will be relevant in the future. 

Being able to think for yourself means you are more likely to be able to detect the lies that people will try to tell you to get you to do things that aren't really in your best interest, like buying something that has the main purpose of compromising your privacy. Math, History, Philosophy, CS, ... all teach you to think in different ways. 

And, in fact, programming is useful in many fields. Even philosophy if you want to examine a lot of texts written by old (dead) philosophers. Science can't do without it anymore. Nor can some aspects of literature. 

The less grown-up answer: Because it's fun.

No, really. 

Well, if it isn't fun then maybe the teacher needs to rethink how the course is taught. Why isn't it fun? Is it the sorts of problems that the students are working on? Are they boring to the students? Is it the way they are supposed to behave? Too much frustration of working alone (or the opposite, I suppose)? Personally, I hate boredom. Or is it that they just don't have any bigger picture of what it is that they are learning, being always lost in the details? You can always ask the students what they "learned today". I used to ask that quite frequently, just to get them to focus on that before they left the classroom. 

Ok. That was a bit grown-up too, but devious. Devious can be good, if done right.