How do cultures become dangerous, as in this case?

Eastern Medical Center (EMC) struggled with its quality indicators, consistently ranking in the bottom quartile of its corporation’s quality measures. Several interventions—training, motivational talks by respected authorities, and financial incentives—were offered. A consulting firm brought in to work with the quality improvement employees noted that the organization’s culture did not support quality. However, the consultants’ proposed interventions were too expensive to implement, far exceeding the medical center’s budget, so nothing more was done. As expected, no change occurred in the dismal quality outcomes.
The CEO was frustrated. He had a favorite saying that people should “man up” and deal directly with problems. One year after the consulting firm’s visit, the CEO took his own advice and fired the chief nursing officer (CNO)
and quality leader. After a national search, a new CNO and quality leader were hired. The CEO had great expectations, and during the first six months after the new employees’ arrival, the quality indicators did record a small increase.
However, beginning in the seventh month, the indicators fell back to the previous year’s levels. As a result, the EMC board met and fired the CEO.
Sally was hired three months later as the new CEO. The board stressed that changing the medical center’s culture was a top priority. Sally had previous experience in organizational development and felt she had the right skills to create a healthy culture at EMC. She also recognized the challenge and difficulty in changing a culture.