Personally I started reading hard SF in the early 70s so it was all I had then for glimpses of the future, and a lot of near-future SF then was based around post-nuclear situations, or robots, or similar, albeit with some superb exceptions from authors such as Roger Zelazny, John Brunner and others.

Cyberpunk didn't really get consolidated as a genre until the 1980s although dystopias had been written about before then. It was in the 80s that the core cyberpunk themes of computer hackers and evil corporations really came together in their current dystopian form.