New bosses generate anxiety. A new cadre of employees does, too.
We often confer onto new bosses all the ill will we developed under the last one, all the gut-tightening habits we so disliked in the previous one, all the unhealed emotional wounds inflicted by the former.
New bosses struggle with the same sort of historical emotional baggage when it comes to a new assignment. All the negative feelings, hurtful experiences, and painful memories of the last gig seem somehow to cast a shadow on the new one.
The net effect is an environment premised on distrust, with the expectation that the "other" will remain distrusted until they have proven themselves otherwise worthy. From both sides of the equation (and I've been on both sides), it is far better to start from a position of trust, good will, honesty, fair dealing, and transparency.
In short, it is far healthier (both personally and organizationally) to form our opinions of the other based on their uniqueness, not in assigning to them the flaws and foibles of someone else.
We all feel and perform better when others afford us a blank slate from which to begin. We'll feel and perform better if that is what we offer as well.