What is missed is free time is just one good you can get. People like different "things". Sometimes that "thing" is free time. Sometimes that thing is more expensive food. Sometimes that thing is a bigger house. Sometimes that thing is... There are a lot of options. If you were willing to live like 1950 you could have the male working 20 hours a week and the female never leaving the home. What people forget is in 1950 having a black and white TV was unusual (though not uncommon) and color TV was still several years away. Your phone was a shared party line. You had one car which wasn't reliable by modern standards.
I think in this case, it was rather cynical. The "free time" the workers got was because they were unemployed. The workers who were still employed of course had no additional leisure time, the added productivity went to the employer.