Sometimes, lower and lower middle class folks (and others) do not adapt or explore the options available to them. There are many reasons but a few include, a lack of adaptation to the ever-changing times. Many workers are still looking for and expecting "secure" jobs or careers WITHOUT any experience, education, or training. We have a surprising number of unskilled workers in America. There are still frightening numbers of people without a high school diploma or the ability to read. Others choose horribly wrong majors in college which lead them to take any job (not a CAREER) just to get some earnings in their pockets even when those earnings will not repay their college debts & cover their living expenses.
Some choose incorrect jobs & careers & wait too long to re-train themselves before the open positions dry up, if they ever re-train at all. Others, are simply not talked to about what they need to do when they are in the start to the middle of their high school education, too often setting them up for a life of hard knocks and learning as they go, which is often costly, wasteful, and simply wrong on the part of those who supposedly "love" them. If these types are lucky, they play the catch up game coming from years behind their peers who had involved parents/families who offered proper guidance & support.
I know people, not just old people, who refuse to learn how to use a computer, despite them being more and more ubiquitous as the years go by. This is a choice to be left behind, plain and simple. There are people who are quite capable of more who choose to be less by not learning a trade, earning a career certificate, getting a degree, or an advanced degree. Yet, they long for the old days when one could walk out of high school with a diploma in hand and get a factory job that would last for the rest of their lives.
Those jobs are just that, jobs, not careers and they are leaving the country whether replaced by labor abroad, forced onto more efficient workers here, or machines. Sure, some of these jobs will be around for decades but many will not. Sometimes, lower and lower middle class folks do not adapt or explore the options available to them.