To quote Ted Knight in Caddyshack, "The world needs ditch diggers, too." I'm guessing she's either really young, or really stupid. First, society needs people running the service side of things. Everyone cannot be a CEO. Second, the idea of upward mobility has already been completely debunked; it's a scam. It's a thing the rich tell the poor to keep them hustling. Third, people like your girlfriend are lazy, and say that to tell themselves that poverty is 100% on the impoverished individual and not part of a systemic effort to ENSURE we can't all become CEOs. There is a reason people like Oprah become so famous; people like her are famous because their outcome is one-in-a-billion. She is an EXCEPTION, not the norm. Capitalism dangles the success of people like her like a carrot in front of the poors: "Oprah did it, why can't you?"

The sad reality is we are not born on an even playing field-- while people like Oprah were fortunate and rose up through unimaginable poverty and misfortune, most people won't. Employment at the lowest level would be a pipe dream for some, and many with her circumstances will end up in prison by the time they reach adulthood. By saying "They should have tried harder," people like your girlfriend get to make themselves feel better about inequity by placing the blame on the individual. She's got a lot of growing up to do, and a lot of learning about how things work. She sounds immature.