The moral imperative to never deny care. Health care receives both revenue and regulation from governments, but not all of its revenue or its regulation from governments. Policy in health care requires mastering technical expertise and assessing difficult situations. Governments treat health care as an entitlement. Health care is expensive.
Insurance isolates all participants form direct market forces.
Almost every health care issue is a moral issue as well. The money in health care draws the attention of people who want some of it. The first solution is usually the wrong one in a complex situation that has not previously been assessed. Health care is not magic. It does not guarantee a cure in every situation, eternal youth for every patient.