Some people don't like scary movies at all. Some only like slasher movies; nothing with the supernatural. Everybody else either likes zombies or vampires. And nobody likes them both the same. You've got to love one more.
I love zombies more.
My friend, N, loves vampires more.
N says they're sexy.
Are they? Certainly, the vampire is a metaphor for sex. There is an element of desire, of carnality, to the vampire archetype. The vampire is a penetrator; and with his penetration and consumption of the 'innocent' infects them with the same carnality, and need to consume. The victims of the vampire are preserved in the moment of their victimhood.
Dracula is Prince Charming, with sex and death all mixed up. Instead of living happily ever after, pumping out heirs to the fairy tale kingdom, Cinderella finds herself infected by desire, trapped in some elegant night-time demi-monde. She never really dies; she never really gets old. Thus, there is also an element of escape;. The vampires victim, though she loses her soul (the catholic in me would relate the loss of soul to the mortal sin of premarital sex), is also disconnected from the mundane world of work and family.
Vampires work as a romantic metaphor for the loss of virginity. Except, instead of the dull, dissapointed, sticky feelings that often follow deflowering in real life, things actually change after you've been with the vampire.
So why zombies?
No one says that zombies are sexy. Even though some of the same elements are common to the zombie and the vampire. The vampire bites, the zombie bites, they both transform their victims. The zombie, however, is indiscriminate. They don't choose a single victim, so the element of seduction isn't there. In fact, there are very few zombie movies that feature any zombies identifiable as characters. There is no anticipation. A zombie doesn't care if he bites you or your friend. And you're not you, once you're a zombie. You rot. You're gross. If zombie movies are at all about sex, they're a very clumsy metaphor for promiscuity and fear of venereal disease. But I don't buy that they're about sex.
Zombies are not about sex. And zombie movies are not about zombies, per se. They're about survivors. They're about making do. They're about being prepared, being creative. It's another kind of escapism; suddenly, the world is very small, and traditional social constraints are gone. Nearly all zombie movies contain looting. Dawn of the Dead (original and remake) is about almost nothing but looting.
It's also about unemployment. People, the survivors, have jobs. Then the zombies come, and there are no jobs. There are no careers. Skills matter a lot. Ingenuity matters a lot. People who love zombie movies nearly always think they'd be survivors. And that they'd be valuable. Being a zombie survior is almost like being a pilgrim, or a pioneer. It's a whole new world, full of dangers, but at the same time with more potential than the old world. Sure, you'll probably die. There are no new worlds left. There are no indian lands to steal. But, if everybody becomes a zombie, all their stuff is up for grabs. And, the old social order doesn't matter.
Who is always sure to die in zombie movies? The social climber. The person who wants to rely on their status in the pre-zombie world for power in the post-zombie world. They never survive. Think of the douchebag with the boat keys in Dawn of the Dead. The Colonel in 28 Days Later.
The fundamental escapist fantasy underlying the zombie movie is that the zombies will come, and transform the world into a brutal meritocracy.