I read that as "studied with zombies while working on her doctorate." It describes the grad school or university ambiance pretty well.
Of course "experts" can always give a reason why some science fiction or fantastic or horror theme becomes popular -- scifi and horror took off in the 1950s because of the Cold War, the Bomb, and McCarthy -- but that ignores the business aspect of show business.
Somebody is always trying to make money out of something. If it isn't zombies it's vampires, and when people get tired of zombies and vampires, there's always werewolves and mummies.
Sure, vampires represent aristocratic longings and sexual fears, and zombies incarnate fear of the unwashed, uneducated, inarticulate masses. But beyond all that, they're established franchises with a known appeal to the public.
Mummies, though, don't really get a fair shake in show business.
Not since Abbot and Costello, anyway.