The older, original, Vampire stories like Dracula seemed to be tied to suppressed sexual desire. In a time when table legs were kept modestly covered, and naice ladies didn't open their bedroom windows wide and recline on their beds in lacy, off the shoulder negligees, awaiting the arrival of their demon lovers.
In the same way I sometimes wonder if perhaps the current fascination with zombies is connected to the rise of homelessness in the USA, with better off people being forced to step over and avoid drug damaged, hopeless fellow citizens, who have fallen through the social safety net?
Perhaps the combination of anger, pity and guilt triggered by dodging scary people and trying not to step in their faeces on your way to work makes people extra receptive to a fantasy world where ordinary, every day people morph into lurching monsters intent on feasting on your tasty brains?
There may be something cathartic about being obliged to blow off their heads with shotguns, or batter them to mush with a shovel. Perhaps it satisfies something inside, and makes it a bit easier to ignore a world that has turned scarier and more cruel since Reagan and successive governments (on both sides of the Atlantic) closed the mental hospitals and cut social security to the bone?