Business majors graduate with an understanding of what it takes to build a business in today's markets. Architects and engineers graduate with an understanding of what it takes to design and create things in today's world.
No they don't. They come out with basic skills, just like CS majors (or doctors, lawyers, and so on), and need to work with experienced practitioners in order to become proficient. The best graduates are usually the ones who spent some time as an intern and got an idea of what actually goes on in their field.