Reporters simply stop suggesting story ideas that always get summarily rejected. A lonely managing editor wonders why nobody ever tells her anything. Bristle Desk becomes part of the newsroom's culture, and therefore harder to break. Unbristling the bristly Newsroom leaders can change cultures and destructive group habits, but such change takes time and patience. And the first step is modeling the behavior you want.
Many editors have no idea how hostile their daily exchanges sound.
They may need to tape a few just to hear them. One editor I sat with for a day had no idea that he shouted at everyone who walked into his office, until I taped him doing it. The staff needs to discuss Bristle Desk openly and decide that it hurts their work and morale. Then the coaching editor can suggest building on that awareness. Since Bristle Desk is habitual and eventually instinctive, the staff needs to retrain its unrehearsed responses.