The American economy has changed and the worker changed with it. Social Security, Food Stamps, Free Lunches, Pell Grants... all that is nothing new. What happened is the middle-class son realized there are easier ways to make a living.
My brother-in-law is 34 and the hardest working man I know. He is a welder and travels all over the South on projects. He makes shucks... I think $35 an hour. That's $72K a year. Try to raise a family on $72k a year... if your wife ain't working you are broke.
On the flip side, a project I was on a couple years ago.. they were paying graduates from Alabama and Auburn $65 an hour if they had computer programming degrees.