Due to a lack of man hours available to teachers, we make up for breadth instead of depth. This is a good thing, as we do not know going forward what we should teach in depth to children. Teaching kids about cam shafts and carburators would be a fools errand, but you only knew that about 5 years ago. However, depth is needed in many areas, we just have to trust people to figure that out on their own, as they are more mobile than an educational system. An example is bit wise operations in computers. Many don't have a clue as to how to use a register in a chip, and we thought we'd never have to again. But encrypting, securely, relies entirely on this and trying to poke holes in it. Now, again, we need the depth there to maintain encryption as a viable idea.