Marx couldn't have said it better. And besides, everything in history books has an unduly magnified place by that standard. Hey, remember that history is written by the winners, e.g., those who did the "spurring".
But more to your point, I doubt you could find many people in any age who don't or didn't want to know what happens after you die. It's the most important question there is, and people never have to be "spurred" by a priestly class to wonder about it.
I would venture to guess that the average Mesopotamian citizen would have gladly ditched metaphysics in a quick second, if they could have ditched their God-Kings along with.
They would have gladly traded it for some other form of metaphysics, but I doubt nihilism would have been a palatable substitute for them, at least not for very long.
So my only choices are nihilism or religion eh? You seem to have a pretty poor opinion of human imagination. Give 9 out of 10 people who didn't grow up saturated with religion a choice between cleaning the stove or attending church, they'll clean the stove. For 9 out of 10 guys, sticking pins through there eyelids is about a tie with attending church. For 9 out of 10 humans, not church-conditioned since childhood, at minimum, metaphysics is a boring, pointless exercise, maybe because it's inherently a boring, pointless exercise.
No doubt there are those who do, on the other hand, perhaps some people rise above their timid and fairly useless, if not dangerous self-absorptions, and find their human-world occupations are a sufficient substitute for obsessively cultivating their inchoate fears to the point where they become fair game for the next metaphysical con artist that comes along.