Interns should either be paid or receive course credit or both. The department cannot prohibit you from participating in internships that are unpaid or for which you receive no academic credit; however, there could be legal ramifications for supervisors and organizations that rely too heavily on unpaid, non-credit-seeking interns (see Department of Labor guidelines for interns).
The short answer is because it’s required for Comm Arts and Graphic Design majors :-) The longer answer is that internships provide students with meaningful work experience in their chosen profession while benefiting the professional to whom he or she is assigned. They provide a link between the classroom and the workplace. They help students gain career experience and portfolio pieces. They help students learn to function as part of a team in a work environment. MOST IMPORTANTLY…Employers look for internships on recent graduates’ resumes.