vba_php,
Younger kids are immersed in tech with their games, so they learn by osmosis and have a different set of motivations. But there is an age range where that was not the case. A lot of people take dead-end jobs because they feel "too old to learn something new." I see it a lot. People hate change, perhaps because forced adaptation is unsettling. If you studied stressors in life, as I did when I was undergoing a lot of personal stress, you would recognize that the top several sources of human stress involve change. Change of job, change of residence, change of living conditions (married or not), change of responsibility (kids come into your life), ... But I digress.
When automation takes over the jobs of older folks, they have nowhere to go because as kids they never wanted to learn. Hell, I retired because the Navy was throwing too many extra training requirements on me when at age 67+, I had health issues and a sufficient retirement nest-egg to finally just say "screw it, I'm retiring." I regret not being with the people because they were great - but I don't miss the job.
Now, as to why certain people are more accepting of menial jobs? You have to look at the work of Herbert Maslow, who was an economist (I guess with a Psych minor?) who studied economic motivation. In a society of poor people, day-to-day subsistence is a massive motivator and getting any kind of job at all is an advantage. Which is why many immigrants start out as what we call "day workers." You can see them lined up in the parking lot at the local Lowe's or Home Depot, hoping to find another day of work.
Maslow found that as you gain in education and abilities, whether through night school or OJT, you get longer-term viewpoints and no longer are content with simple subsistence. You start thinking long-term survival, i.e. socking some funds away for that rainy day. The more you learn, the more you become involved in your community. It is important to realize the truth of Benjamin Franklin's old saying, "Hunger is the best pickle." When you are hungry, you are willing to do a lot.