So there definitely is a place for canon when different writers are creating works in a shared reality. There's also a place for canon in an author's own distinct creations. One of the quickest ways to lose a reader is to contradict your own, previously established rules. What I've never understood, however, is how some people can attempt to impose canonical rules upon a genre.
Just to be clear, I'm talking about zombie-themed fiction here. For some reason, other archetypal monsters haven't suffered this same fate. No one argues, for example, that a vampire isn't a vampire if it doesn't behave exactly like Count Dracula; no one works themselves into a frenzy because Stephen King's werewolves get "wolfier" as the moon waxes, as opposed to transforming only by the light of a full moon. Yet for some reason the walking dead are treated differently.
There are some hardliners out there who claim that your fictional creatures aren't "true" zombies unless they follow the rules set by George Romero in his classic Living Dead trilogy. And I'm not just talking about fans of the genre, but other authors as well. To me, this is absolutely ludicrous. Why would I limit my imagination by adhering to someone else's preconceived notions of what constitutes a zombie? And, if I did, what would separate what I'd penned from fan faction? Simply because the original source material is in public domain? Because I only borrow the general ideas and not the same protagonists? Either way, the outcome remains the same... I would still be playing in someone else's sandbox.
Don't get me wrong. There's nothing wrong with fan fiction. It can be a lot of fun to imagine different events stemming from your favorite books or films. But as authors we have the ability to create entire worlds to our own specifications; as artists, we have the ability to lend new perspectives and ideas to fictional realities, to make them distinctly ours. And it really does boggle my mind when I try to figure out why someone would willingly trade in that freedom.
However, even if we take creative differences out of the equation, it seems that zombie canon is an extremely subjective thing. In a lot of ways, it reminds me of an all-you-can-eat buffet where people pick and choose what they like and leave the rest behind.
For example, Romero-esque canon states that zombies don't run. They should only shamble along slowly with their true strngeth being in their numbers, not their individual speeds. People will argue this until they're blue in the face: Zombies... don't...run. To accept this piece of canon, you have to totally ignore the fact that the zombie who attacked Johnny in Night of the Living Dead ran after the car when Barbara was trying to get away. Was he as quick or coordinated as the sprinting undead in the remake of Dawn of the Dead? Of course not; but, by the same token, he wasn't just simply shuffling along either. If this isn't enough evidence, then re-watch the original Dawn of the Dead. Right after Ken Foree gets a cup of coffee out of the vending machine, he's attacked by a pair of zombie children. Children who run to attack him.
Returning to the cemetery scene in Night, however, we stumble across more pieces of contradictory canon, the first being "zombies don't use tools". I'm sorry, but when the cemetery zombie was attempting to break the car window with a rock, he certainly seemed to be using a tool to me. It's not as if he just happened to be holding that stone when he stumbled across Johnny and Barbara. No, he attacked the car and when the initial assault proved futile, looked around and scrambled after something he could use to break the window. This also goes against the so-called canon stating that zombies are incapable of critical thinking. The zombie was presented with an obstacle and found a creative solution to overcome it.
One piece of proposed zombie canon, though, is pretty consistent with Romero's vision: zombies have to be reanimated corpses --anything else simply isn't a zombie. Personally, I strongly disagree with this point of view as it seems overly simplistic. To accept this line of thinking, you also have to accept that the only thing which makes us human is a beating heart and functioning pair of lungs. To me, the infected in Pontypool and 28 Days Later are undeniably zombies, even if they are technically still alive. Everything which makes them human is entirely gone; they exist only at the most base and primal levels and no longer seem to be in possession of consciousness as we know it. The person they used to be is, for all intents and purposes, dead... even if the body isn't.
Besides being a pet peeve, I think there's also an intrinsic danger in applying canon so liberally. If we all agree to only create works which strictly adhere to a set of rules governing all zombie-themed literature, the genre will quickly become stagnant. We will be subjected to the same types of characters, dealing with the same set of circumstances, and will basically write the same book again and again. We would, in essence, become the very things we write about: soulless husks going through the motions while lacking the life-giving spark of innovation and creativity. At that point, you may as well put a bullet in the genre's head, for it would truly be dead.
"When we all think alike, then no one is thinking." ~ Walter Lippmann