> When they see leaders take credit for every success and blame others for every failure, employees’ morale sinks and their self-confidence wilts.

I've seen this first-hand. It was very sad to see someone spend so much energy yet reap so much damage. They don't do it out of malice, they simply don't notice it and are resistant to criticism which they perceive as personal attacks.

Developers stalled in their skills, communication between departments ceased and people started leaving. Within a few month the entire development team was gone.