I have never been subject to a "gagging order" so may have misunderstood the circumstances under which thy are imposed. If that is so I'd be happy to receive correction.
However, from what I read in the papers there seems to be a great deal of opprobrium heaped on the organisation that imposes the gag, and the silenced whistle blower is hailed as something of a hero. But surely what has happened is that the whistle-blower is offered, and has accepted, a bribe to keep quiet. Admittedly some of these bribes must be very difficult to resist: one in the news at the moment is said to be in the region of half a million pounds. However, the whistle blower doesn't have to accept the bribe: if he or she is so terribly concerned about the wrong-doing of the organisation he or she could forgo the bribe and still speak out.
There seems to be to be moral culpability on both sides. What is needed in all large organisations, public and private, is open and democratic representation of all the "stakeholders" - employees, the community affected, and customers, clients or patients - as well as shareholders if the organisation is in the private sector, so that the clique in control is held to account.