Turning a zombie pandemic into a generic disaster movie robs the zombies of their dirty, nasty edginess and robs the disaster of its epic scope.
Max Brooks' novel 'World War Z' is one of the greatest zombie stories ever written, partly for reasons that make it basically unfilmable.
The novel 'World War Z' is told from the perspectives of so many people - speaking to the narrator - that there's no way a movie could capture all of them. Still, the idea of turning a zombie pandemic into a war story is fascinating and could have translated easily to film.