it suggests some kind of profound aesthetic/cognitive shift in human perception in a scant 45 years.
Oh hell yeah... We've seen it in just the last 15 years. Changes in societal attitudes, such that one sensibility looks completely alien from our eyes, or we project current sensibility (incorrectly) onto a past time ..
Just look at how people track ideas and values seen in movies barely 10, 20, 30 years old. They freak out at something that was completely innocuous back then.
Paradigm shifts are happening all the time.