Certainly people differ from time to time, but I think people have biases towards such bottoming out of reality. If you bottom out with people you are more likely to see some sort of God as the prime mover. The rock person may be more likely to imagine the first rock. Descartes believed in God as did most intellectuals of his day. He might have been attracted to Tegmark’s universe as mathematical reality. Krauss describes a ‘Universe from Nothing’, which may seem an oxymoron, but so are all of the bottoms.