If you had military, or jobs with some kind of remove, maybe things that most wouldn't have a stomach for, people like him probably ended up there. Politics, too, but they need to have some understanding of emotions in order to emulate and manipulate them, and a reason to put in the effort.

[Like worming into Quentin's life. His heart.]

That's probably what you saw. Him swapping masks when he realised one wasn't working on you.