Life, Death, Life and Zombies!
It's not a new concept, it has been there for many years. Older than you and me I believe. But why on earth would it be of any good?
Funny thing is that its the same concept that has carried forward over the years and no matter what you do movies and video games based on such concepts generally do well or average at least. (Exceptions are always there, but that's not the point).
Coming to the point, I believe that there is a deeper connection with the life as we live it and zombies, otherwise, I don't think people would even give it a second thought.
You live a good or bad life, but you're alive and then suddenly you die and remain dead for a while, rotting away, dead as you are then suddenly a part of you wakes up. Maybe without a soul or recognition of what you are or were before in your past life. Even if you do remember the part of you that controls you doesn't want to control you anymore. Lets you go free and then you do what the situation requires you to do, either be killed or kill to survive.
The concept of zombies in a way is based around human existence. When humans live their lives the first time, they live as normal people, trying to cope with the social order of the society, living out their lives as much as they can to the fullest. They die and rot beneath the earth, souls go somewhere else and left behind is a void that needs to be filled.
According to many beliefs there will be a resurrection one day for all humans. It reminds me of the same concept again, humans get up and walk as zombies over the face of the earth. Having no souls they don't know what to do or whom to kill or eat.
Losing one's soul seems to me like a gradual process not done in a moment or so. Effects start showing early on in our lives. Feelings of greed, doing better than others, not liking others winning, wanting to show them off, desire to beat others, kill too in some situations. Some people control these emotions, others can't even in their lives. So the transition to the state of a zombie is gradual but it's happening.
I suppose this is the reason why humans are attracted towards this concept even though sounds very grotesque and dirty even. But again, it's much more close to reality that you'd think.