Why must whistleblower employees stand alone?

The man with the whistle is often in a lonely place, as many a referee has discovered to his cost. Retribution against these whistleblowers can occasionally be swift and merciless, as the referee of a certain high-profile GAA match between Meath and Louth not so long ago found out to his cost.
But, increasingly, the whistleblowers are symbols of dissent, challenging authority in workplaces rather than serving as symbols of authority on the sports field. Some have challenged their employer and fellow workers, within the health service while others have operated to expose activities of governments.