I have managed startups as well as mature companies. I personally have never been part of a business that has publicized salaries, except as required by law in the context of securities regulation. Publicizing salaries might serve the personal interests of certain kinds of founders-those who want to appear benign and generous in the case of high salaries, or those who want to appear mean and all-powerful in the case of low salaries. There does not appear to be any legitimate business purpose served or advantage gained by doing so however.