When I was about 14-15, I loved Stephen King's "The Stand" and some of my friends liked it too. The youth fetish culture didn't really exist in that time and place, but the book and its post apocalypse world fascinated us. We talked out what we'd do and how. Find an island. Rescue damsels. Train dogs.
It's a persistent sort of a fascination. Interestingly so. It would be fun to find out more about the art history of zombie apocalypses.
Under this, in some way, is the fact that major catastrophes and cultural "rebooting" plays a pretty substantial role in human history. I find the idea that the world's flood myths (Noah, Atlantis..) relate to catastrophic flood events. Religions tell us about past catastrophes and promise future ones. There are some pretty interesting suggestions that the early fertile crescent civilizations' (eg Egypt) sudden rise are actually rebuilding events following the catastrophic demise of earlier (EG Gobleki Tepeh in Turkey) civilizations. There's also a lot of genetic evidence of major population collapses at several points.
There's also post war baby booms and some other bits and pieces suggesting that we are hard wired to think apocalyptically.
Interesting stuff.