Why are there so many pointless subjects in High School?

If you're in year 11, then you'll be taking exams this year. After that you can leave if you like, but you won't get very far. This world is very different from your dad's. He could be a "self-made man" but today employers want a piece of paper, even if it's from a trade school. What you really need to do is decide what you want to do with your life and look for an educational institution (not necessarily a college) that will help you get there.