Help settle this debate. In 28 Days/Weeks Later nobody uses the ‘z’ word - they are referred to as ‘the infected’; infected with the Rage Virus which turns them homicidal to the point of ignoring the need even for food.
But, you don’t need to shoot 'em in the head - anything that kills a human will kill them, and they’ll eventually starve to death. The virus doesn’t “reanimate” either - the infected are not killed and brought back to life, they are not the living dead.
On the other hand, they have an insatiable bloodlust for the deaths of plucky survivors, are highly infectious and will not attack each other. If it hisses and bites like a zombie…?
To me, it’s a technicality. So, I chose it still should be classified as a zombie film.
It’s just another mutation of the genre. Probably to try and ground it in a way that makes a bit more sense, since a traditional, reanimated corpse that eats brains to keep viable is a magical suspension of disbelief. What we know about physiology, well, this can’t happen. At all.
So, the genre continues to experiment and change its genotype. But the phenotype is still the same. Survival and indefinitely running from mobs of slow, mindless, bloodthirsty humans — amongst the remains of the modern world to find refuge or be painful reminders of life before… and it can happen TO YOU!
If you read the source, it’s not that simple. It seems that the objection was to the fact that the creatures in these movies were able to run. Since zombies are understood to stumble, he seems willing to accept the idea that the creatures from these movies are not zombies.
By that definition, Count Dracula was a zombie and I don’t think you’ll find many people agreeing with that.
As I noted above, to me the defining characteristic of zombies are how they act not their origin. They’re supposed to be a mindless violent mob. You can’t reason with zombies, you can’t scare zombies, you can’t befriend zombies. They’re just a force of nature, like a hurricane or an earthquake.
I’m okay with subdividing the genre into “fast zombie” and “slow zombie”, rather like the division between action movies and horror movies, which also can have overlapping elements.
What I object more to is that 28 Days/Weeks were bad movies.