It is not quite true to suggest that the only photographers collected by museums are the MFA crowd with their artist's statements and postmodern conceits.
What IS true is that museums are not interested in work that is simply variations on a well-mined theme, photographs which are more or less commodities. Attractive landscapes, weddings, store-front portrait shops, product photographs, theater photography Suitable For The Brochures, Web Sites, and Posters, and so on.