To the extent this is true, its not the actual 1950s, but a mythical image of the 1950s created later, that's mostly associated with that particular time because its a distorted image of what the world was like prior to the supposed liberal reengineering of society in the 1960s and beyond. (And probably because at the time it started to coalesce, "the 1950s" was an easily-romanticized childhood time of the audience the image was meant to appeal to.)
