I think the general anxiety of the 1960s - '70s spawned our interest in the living dead. When people worry about the end of their world, they need a safe vessel for all their fears. Zombies provide that vessel because they're 'safe.
I think the fascination with zombies is that they don't obey the rules of monsters. The first rule of monsters is that you have to go find them. You have to make a conscious choice to go to the swamp or the desert or the abandoned summer camp.
If you believe you can accomplish everything by "cramming" at the eleventh hour, by all means, don't lift a finger now. But you may think twice about beginning to build your ark once it has already started raining