it was a limited consideration in the 50s, but basically bolted on the side of robert-moses-core with the odd rootcellar called "fallout shelter" as a marketing gimic in new developments.

round about 1:07 in everyone's favorite nuclear documentary is an example

That's actually not that new. I think that was part of it.

It is important to remember why cities were building highways through the fifties and sixties; why the federal government was promoting low-density suburban development and why companies were moving their corporate head offices to campuses in the country: Civil defense. One of the best defenses against nuclear bombs is sprawl; the devastation of a bomb can only cover so much area. Shawn Lawrence Otto wrote in Fool Me Twice[.]

https://www.treehugger.com/why-sprawl-was-caused-nuclear-arms-race-and-why-matters-more-ever-today-4854403

Not to mention the stuff we put in our houses and make them out of is like 20x more flammable than back then.

Destroying critical junctures for energy and transport infrastructure won't be a problem so long as fewer people are in the immediate proximity of the blast

Look if Joe Brandon is gonna doom us all, at least let me get my appletini on 💅💅💅