The point TGGP3 is making is that they didn’t choose to do bad things, and so are not bad people—they’re exactly like you would be if you had lived their lives. Always remember that you are not special—nobody is perfectly rational, and nobody is the main character in a story. To quote Eliezer, “You grew up in a post-World-War-Two society where ‘I vas only followink orders’ is something everyone knows the bad guys said. In the fifteenth century they would’ve called it honourable fealty.” Remember that some Nazis committed atrocities, but some Nazis were ten years old in 1945. It is very difficult to be a “good person” (by your standards) when you have a completely different idea of what being good is. You are displaying a version of the fundamental attribution error—that is, you don’t think of other people as being just like you and doing things for reasons you don’t know about, so you can use the words “bad person” comfortably. The idea “bad people deserve bad things to happen to them” is fundamentally flawed because it assumes that there is such a thing as a bad person, which is unproven at best—even the existence of free will is debatable.
There are people who consider themselves to be bad people, but they tend to be either mentally ill or people who have not yet resolved the conflict between “I have done X” and “I think that it is wrong to do X” - that is, they have not adjusted to having become new people with different morals since they did X (which is what criminal-justice systems are meant to achieve).
Utility has a single, absolute, unexpressible meaning. To say “X gives me Y utility” is pointless, because I am making a statement about qualia, which are inherently incommunicable—I cannot describe the quale “red” to a person without a visual cortex, because that person is incapable of experiencing red (or any other colour-quale). “X maximises my utility” is implied by the statements “X maximises my deity’s utility” and “maximising my deity’s utility maximises my utility”, but this is not the same thing as saying that X should occur (which requires also that maximisng your own utility is your objective). Stripped of the word “utility”, your statement reduces to “The statement ‘If X is the end goal, and option A is the best way to achieve X, A should be chosen’ is tautologous”, which is true because this is the definition of the word “should”.