That particular period of time was wrought with geopolitical anxiety probably to a greater degree than today from my American perspective. It seemed like Democracy itself could be extinguished on Earth in the early 40's, the late 40's and 50's were tempered by the threat of nuclear annihilation at any moment, the 60s was a time of social upheaval in which more people than we would like to admit were very strongly against civil rights and did actual bombings and murders throughout the country to oppose them, and the 70s was marked by economic anxiety (stagflation) and the collapse in trust of the US government by the general public along with new popular awareness of serial killers and the beginning of much deeper interpersonal distrust which exploded in the 80s. Certainly there were plenty of rosy things through the period as we also have now, but there was plently of material for sci fi authors to work with. My favorite sci fi novel, The Forever War, was a barely veiled allegory of the author's own experience being drafted to go to vietnam.