Every time they do this (or... fail to publish, which is so much easier...), the media digs a hole of distrust that is ever deeper and wider.
And the progressive believers INSIST that there is nothing wrong. Because for them to admit that there is a bias calls everything into question.
The belief system IS a religion, or a substitute for one, and cannot be trifled with by those who wish to be part of the group.
The left has managed to get believers into positions of petty power, from HR minions to teachers, and they're not afraid to wield it.