Our family has a Zombie survival plan but not because we expect Zombies. We do expect at least one disaster in the PNW in the next 50 years. If could a volcano, earthquake etc.. The point is to be ready for anything with Flashlights, Food, Shelter and all you need to survive a partial collapse (or complete) of the infrastructure that supports us. Plus we have different rally points for the family depending on what kind of disaster happens, we didn't plan for sparkly vampires but we did draw up plans for Mt Rainer, Mega Quake, Nuclear/Bio Terrorism as well as Zombies.
To sum up - People may laugh at us because we have what we call the World War Z plan but really its about being prepared for any disaster.