Most of the big name artists that do sell work and books of their work are faculty at colleges and universities for their income. Those that aren't faculty are taking commercial jobs. For example, Jim Stone, author of A User's Guide to the View Camera just recently retired from the University of New Mexico's art department. Jerry Uelsman is Professor Emeritus at the University of Florida's art department. Keith Carter is the Chair of the art department at Lamar University in Texas. Stephen Shore is a professor at Bard College. Abellardo Morell is teaching at the Massachusetts College of Art and Design. Alec Soth has a commercial studio and does work for Magnum. Gregory Crewdson teaches at Yale as adjunct faculty. They all went to school and earned an MFA in photography. This wasn't to teach them to take photos, it is the required degree to be able to teach and earn a faculty income while making their photos.