You'd probably also be surprised at just how many millionaires who used to work in factories there are. 40 years of union wages, plus pension, plus investing in a mutual fund. I obviously can't prove it here, but I'm from a blue-collar factory city and trust me, some of those people have multi-million dollar retirement funds.
Granted, you can't replicate that kind of success today, but there are people who didn't work "elite" jobs in possession of millions.