In one sense I wonder if there ever was intention to make middle class rich... Increasing circulation allowed them to spend more money thus increase value of corporation same goes for pensions. Which then later were screwed out of the money stored there. Their value was to pump the stocks higher...
That's why the idea of the "middle class" was invented. You either live off the land/capital or you work for those people. You can't make the middle class rich enough that they don't have to work otherwise they'll realise they were working class all along.
Also class warfare. Can't have the working class and middle class team up and beat the rich... So have to give at least middle class some aspirations. I think elite is doing same thing with culture war now... Split them up and have them fight about something inconsequential instead of seeing true levels of inequality in wealth...
