Because it is a guide to make your way for being a successful entrepreneur.Successful entrepreneur started in learning then after that is applying then success will come.Without proper knowledge how can you survive and understand the world of business.
Being a successful entrepreneur is not by all means that you must study economics at the university, it is just has a lot to do with your zeal to learn in the real world and make use of some of the available resources. Most of the wealthy men today never studied economics in the university and sure, some of them may eventually have gone to business schools, but that is more like after years of setting up the business, so as to be able to help and guide them to do things better.