While the vampire (especially the gothic mode) is a study in the repulsion/attraction dynamic the modern world feels toward hereditary aristocracy, the zombie narrative allows anyone to imagine themselves to be free in a depopulated world filled with riches. It is a anti-authoritarian fantasyscape. All the (primarily masculine) skills the modern world has little use for become paramount in the post-zombie apocalypse: self-reliance, individuality, gun-play, mechanical inventiveness, bravery. Just as the image of the space-age / interplanetary pioneer was crucial to Heinlein's vision of expansion libertarianism, the later-day zombie narrative can attract those bored with the inaction and routine of daily life in the modern first world.
This renders the zombie narrative a portion of the survivalist fictions whose extreme expression is the Last Man On Earth trope.