The departures are a result of what employees widely describe as a dysfunctional work environment, abysmal morale, and the lure of private security companies paying top dollar that have proliferated in Washington since the Sept. 11, 2001, attacks.
via Top-level turnover makes it harder for DHS to stay on top of evolving threats – The Washington Post.
So two of the three factors are directly within the control of the agency head. Hmmmm . . . . Perhaps we ought to pick a different type of agency head? Bruce Schneier?