More obvious explanation is that the movement really took off after the World Wars, as there was a huge labor shortage on the market to be covered, in the form of a whole generation of young men who never came back from the meat grinder.
And many women spent WWII in factory jobs or even more directly combat-related roles especially in Europe. (Just finished reading a book that mentioned how Mary Churchill--daughter of that Churchill--ended up commanding an AA battery.)
While, of course, the period after is probably widely seen as classic white picket fence suburbia, the WWII experience couldn't have helped but set some changes, however slow, in motion.
