I think it's just how some people comprehend this kind of stuff. Me included! I'm sure no one would laugh at this if they were there, just a coping mechanism that kicks in.
If I really contemplated it it would drive me mad, that's all Sky.
I'm not making fun of either incident, but I do think the thread title itself is silly and borderline hysterical, so the posters couldn't help devolving the thread into the best way to kill actual zombies.