I remember talking to a coworker at a tech startup once. He was leaving to go work for some like military intelligence spy company. I was like, "But what if they have you work on something fucked up, like spying on innocent people, or sending drones to kill people?" He was like, big shrug, the pay is good.

Some people just don't care about other people. He was nice to people he knew, when it didn't really cost him anything.

Our society isn't really set up to discourage that kind of worldview. That kind of selfish person typically thrives.