Petroleum is used by everyone right? And it's a literal fossil. I wouldn't call it a fossil because all terminology has lore, but the idea as I understand it is that it's an artifact that outlived the context it was originally relevant in.
I think foo never outlived what it was from the beginning - a way to harmlessly goof around while describing complex systems & patterns.
So, really dunno why the commenter above wanted to atribute all the fooness to something "ancient".
PS. Unsure why to mix petroleum into this discussion..