I sorta think we should have a tiny bit more of a guideline for this category if it sticks around for next year. My thinking: The nominees are essentially the protagonists of their own zombie apocalypse story. Thus, even if they're in a location that should be easily kept clear (like an aircraft carrier in the middle of the freakin' ocean) or just out in the middle of nowhere with almost no people around who could become zombies (like me) they MUST encounter and have to survive zombies.
Notably, Mog still gets craptons of votes that way, for the reasons he and I have both spelled out