People are murderers if they kill other people. They are not murderers if they let other people die when they can cheaply prevent it. For instance I am not a murderer if I spend a couple of hundred dollars on clothing rather than sending it to a decent charity, even if the predicted result is that one more person will die.
People don’t want to be murderers, but they don’t mind letting people die, except those who are close to them. People also don’t like or respect murderers, but they don’t mind others letting people die, except people who are close to them. People don’t like being murdered or being allowed to die equivalently, regardless of whether those involved are close to them. It is interesting that people’s treatment of others’ lives correlates so with how third party observers deal out like and respect, rather than how the person whose life is at stake feels about it. It is commonly assumed that killing people is bad because we care about the person who gets killed. This might be what we think about when we are condemning murderers, but it doesn’t predict our actions at all well.
Humans aren’t evil here in the same sense that we think of someone who kills for a pair of jeans as evil. It’s not purposeful. Most people believe that they do care about other people’s lives, because they have great trust in their emotions to tell them when something bad is happening. They never check this. But what do you do when you find your emotions do not tell you this at all? One response is to spend yonks trying to justify things like physical distance and action vs. omission as being morally relevant while taking credit for being wonderfully deep. This is evil.