Maybe they once did, a long time ago…
The Journalists Creed:
The Journalist’s Creed was written by the first dean of the Missouri School of Journalism, Walter Williams. One century later, his declaration remains one of the clearest statements of the principles, values and standards of journalists throughout the world.
Society of Professional Journalists Code of Ethics—the preamble:
Members of the Society of Professional Journalists believe that public enlightenment is the forerunner of justice and the foundation of democracy. The duty of the journalist is to further those ends by seeking truth and providing a fair and comprehensive account of events and issues. Conscientious journalists from all media and specialties strive to serve the public with thoroughness and honesty. Professional integrity is the cornerstone of a journalist’s credibility. Members of the Society share a dedication to ethical behavior and adopt this code to declare the Society’s principles and standards of practice.