First, there is the seal-of-approval aspect. When you claim (and, of course, appropriately receive acclaim) that your program is accredited, you demonstrate to students, parents, counselors and others that your program is "in the zone" of programs that meet national standards. In some professions, students may only be able to proceed from your program to their next step of taking required examinations if your program is "in the zone." So that seal of approval is mighty important to students and to you.
Second, there is the progressive aspect. Quality equals meeting national standards, of course, and then exceeding them. Quality is stepping beyond a minimum (the Standards) and doing even better. Quality is being even better this year than you were last year -- and figuring out how to be better yet next year. It's this approach that explains why leaders in accreditation often explain accreditation in terms of "continuous quality improvement."