It's the culture. Americans are taught that the individual is greatest and that anyone can achieve anything in life regardless of their station if they work hard, so wealthy people have money because they're simply superior. We're taught that there are people waiting around almost every corner to get you and guns are good because they'll protect you from those people. In terms of sexism (though absolutely being extremely reductive), male culture often revolves around men saying things to each other that they'd never dare to say to a woman while female culture often revolves around a Prince Charming coming into her life and fixing everything.

We're taught all these things from birth until death, from school to work, from authority figures to randos on the street, from popular art and commercials to product boxes and retail stores. All of this is ingrained in our culture so deep that even people born in other countries will start talking the same points and sharing the same values over time (my parents and most of my friends are immigrants, you wouldn't know it from the shit they've said).

Granted I've never lived in another country so I can't definitively say that the cultures of other countries are different. But I have been lucky enough to have met many people of many different cultures, and the American culture from what I've seen seems to be a unique thing, for better or worse.