I think it is interesting that a majority of the changes happened between the 50s and the 70s. I guess it might be attributed to post-war optimism and the golden age of capitalism that lasted just about the same era.
The "down" arc: thalidomide, Chernobyl, Challenger, oil crisis, "Silent Spring", global warming, and the rise of environmentalism.
(someone have that graph about all the good things stagnating in 1971?)
Environmentalism and precautionary principle thinking in general steer away from techno-optimism by asking "what could go wrong with this?"