I think obviously your concerns are very well-founded but it is worth remembering that almost every pre-scientific society has a mixture of creation myths and metaphysical explanations for natural phenomena. In fact, you only have to look at the persistence of 'creationism' in the US, for example, to see that it isn't limited to pre-scientific societies either.

Even the modern world needed to understand both plate tectonics and radioactive decay before anything resembling a satisfactory understanding of Earth's geology was possible.

I don't think it would be calling the Ancient Egyptians savages for their interpretation of the Sun as being rolled across the sky or for the Ancient Greeks to regard lightning as the anger of Zeus etc. Nor would I be surprised to find that the many different Native American cultures who must have interacted with Yellowstone will have had their own interpretations and explanations for its geothermal activity etc.