There seems to be a stigma associated with blue-collar work that wasn't there a few decades ago. People just don't seem to want to learn a trade any more. This Old House (anybody else watch that?) had a program to teach people carpentry, electrician skills, maybe HVAC, but they were having trouble getting anybody interested, and many of the people who went through the program decided they would rather get into management and tell other people what to do than do the actual work.
Perhaps young people just don't like physical work unless it takes place in a gym. Personally, I get some satisfaction from makings something out of nothing, and that usually involves physical work.
I used to love working hard. Of course, I had a lot more energy back then. I moved into a new house today and that wasn't my idea of fun, but I kept up with the guys I hired to help. They were probably in their mid-20s. I had 40 years on them. I don't remember my back cracking when I'd stand up when I was their age, though. Ouch. Of course, moves when I was in my 20s were fueled by beer and pizza.