It’s just a useful scenario to war game. Really if you throw out the fantastical element what you have in a zombie scenario is this:
80% of the people are gone
about half of them have been “replaced” with highly contagious psychopaths
the infrastructure is gone
command structure has become nearly impossible to maintain
there will be no resupply
What do you do?
It’s an excellent worst case scenario to study. Made more useful by the large quantity of movies, books and now even TV shows that have worked in that ground, giving you a lot reasons why things that seem like good ideas might not actually work. All the best stuff within the genre is focused a lot more on how humans deal with this situation and how the situation changes them than on the zombies. There’s a lot of fertile ground for people who are in charge of people to consider.
Aren’t we operating with at least 3 out of those 5 conditions every day?
50% “replaced” with highly contagious psychopaths - democrats...
infrastructure is gone - check out the condition of our roads, bridges, water and sewer systems...
command structure is nearly impossible to maintain - Obama mal-Administration...