Their Asimov was probably Verne, which already was trying to predict the future before them.

Around Verne's time (and a little later too), it was the 1889 Paris Exibition, the invention of the airplane, telegraph, lightbulb. Those were worldwide phenomena.

Asimov (and others of his time) probably read all of that. He then saw the "new science": computers, space, the atom, and wrote about those.

I also believe the great recession contributed to a certain degree of awareness not to be too optimistic.

It seems very obvious for me to trace the pedigree of this futurism to those references, it's all over his writing. Foundation reminisces about a lot of those ideas.

Also, it seems very obvious that politicians and regimes of all kinds used the public excitement with science as a populist move, not the other way around. Those ideas never came from them.