mdd: I agree. Some parts of secular education is needed to make a parnassah. But why teach trigonometry to someone who will become a car salesman? Or geometry to someone who will sell shoes? How will either of them gain through learning biology?
If we were talking about a school that taught specifically the subjects needed to engage in a given field of work, I would think that is a great idea. But I think to teach everything in case some of it is needed is bittul Torah in Yeshivos where they would otherwise be learning gemarah.