That tracks back to the Horatio Alger stories. Before that, manifest destiny. That wasn't exactly the same, but you can see how that idea tied into the pull yourself up by your bootstraps idea. These ideologies that pop up and gain popularity are always stacked on top of ideas that didn't work the first time around, but people liked because the eased some of that existential angst we all carry around.

Ultimately that's what it gets down to. I'm not so bad if I'm better than someone else. Wealthier, more moral, prettier, smarter. Whatever.

Our culture assigns moral worth or weight to wealth. That's why that dynamic works better and more consistently when wealth is attached.

He just couldn't be a murderer because he's successful. She, on the other hand, is a gold digger who only wanted him for his money.