Why Would a Course in Marketing be Helpful?

Why would a course in marketing be helpful even if you don't pursue marketing as a career?

Marketing is used everywhere in today's society and is a main aspect in running or working for a successful business. Literally everywhere you look, on the t.v., computer, magazines, billboards, etc. there is some form of marketing. Therefore, I personally think that a course in marketing would be very helpful to anyone even if they don't pursue marketing as a career. Many other majors for college students today also teach ways to market a product. I work at a landscaping company over the summer. The owner never graduated from college, but has one of the most successful businesses around. However he does very good work and has to make sure that he continues to do quality work so that he can keep his customers coming back. In another course that I'm taking, called Management Information Systems we have a student who is trying to come up with a product for all terrain vehicles and dirt bikes. He wants to have two products, a high end and low end product. In order to make this product of his be successful, he will have to market his products at different shows and hope to attract clients.
Do you think someone starting a business with no marketing knowledge could be successful? Should there be more marketing classes available to students?