I think this (changing views on csa) and other instances like this commit a fallacy of logic. Your examples demonstrate this very well.
What I mean is that some folks see human culture as linear as time itself...that current society is subject to chaos theory...as in "things were perfect at one time"----garden of Eden or whatever....and we continue to lose order to the point we're left with a lack or morality and creeping depravity that gets worse with each generation. Of course that's bunk. Humanity has alrady carried the good and bad...it just manifests itself differently with subsequent generations.
If you have seen "The Shining"...there is the point where the phantom bartender Grady says to Jack, "You have always been here..." Evil has always been with us...but tolerance for it evolves...
"His voice rose under the black smoke before the burning wreckage of the island; and infected by that emotion, the other little boys began to shake and sob too. And in the middle of them....Ralph wept for the end of innocence, the darkness of man’s heart…”. -----William Golding