Have you ever worked for a leader who was not fair? Showed favoritism? Was weak and ineffective? Who said one thing and did another? Who did not communicate well? Who did not see his weaknesses? What was that experience like?
Engagement can not happen when the leader is not leading or is leading ineffectively. Employees are going to drift and many times leave over time. People do not expect their leaders to be right EVERY time. People are looking for someone who is sincerely trying to make it better and who have personal integrity.