Moral hazard and the decisions that it may influence have an inherent omission bias: while I cannot force an alcoholic to take disulfuram (without a court order), the alcoholic cannot force me to provide him with alcohol. The status quo is the moral reference frame.
Moral hazard stems from a fundamental underpinning of human behavior: we learn appropriate avoidant behaviors through pain. Children with a mutation that prevents them from feeling pain have short lifespans because they do not learn appropriate avoidant behaviors, as detailed in this poignant NYT article. It is a striking article, and I don't think a person could have a full appreciation of moral hazard until they read it, so please do.
If there is moral hazard in general, it certainly exists in medicine as well. I will illustrate this through several examples.