Yeah no, not buying that if you actually believe anyone chooses to be poor. But I'll pretend for a second you aren't lying. If you work hard, but don't have the opportunity to make a better life for yourself, you will still be poor.
Everyone has opportunities if they know where to look—even people barely scraping by on minimum wage. They just have to make the right decisions by the time they reach high school—living with roommates to keep their costs down, waiting to have kids until they can afford them, and saving every penny they can so that they can afford to go to college. Once they've passed that hurdle, it gets somewhat easier, but many never even get to that point, in large part because nobody instilled in them the importance of saving money.
Mind you, the poor don't have the same opportunities, and it is harder for someone starting out poor—particularly if their parents are also poor—but having fewer opportunities is not the same as having no opportunities, which is why I think it's important to spend at least as much effort at educating the poor to take advantage of the opportunities that they do have as we spend on trying to artificially create additional opportunities (which is, at best, a temporary solution that only helps the current generation and must be continuously funded).
And learning money management skills isn't just important for the poor. I've known highly intelligent people working in high tech who are at both extremes—people who spend almost every penny that they earn on getting new cars and computers almost every year, and people who are the polar opposite, never buying a new car because they don't want to lose half their investment in the first year. One of those groups is going to be in a position to retire early, and the other is probably happier right now. On the one hand, you want to retire early enough to enjoy your retirement years. On the other hand, you could die in a car crash the day before retirement and not get to enjoy any of your savings. It's a trade-off.
The important thing is not the particular balance of spending versus saving that any given individual chooses, but rather that the individuals intentionally made the decision after carefully considering the alternatives by looking at the numbers after gaining enough knowledge to understand the ramifications of their decision.
Every dollar that you put into a 401k at age 22 will be worth more than twenty dollars at 65 (statistically). So whether your personal goal is to retire at forty or live a more luxurious life and work until you're 70, whether you plan to have no kids, one kid, or ten kids, it is important to start thinking about financial planning for retirement by the time you take your first job. Unfortunately, many people (both rich and poor) don't do that. The critical difference is that people with high income can mostly get away with burning through most of their income, whereas people with low income can't. And that's why we need to spend more effort on financial education of our young people; education is the great leveler.