When challenged by the dictum that people often confuse nature with history, the response is to abandon arguments from human nature and replace them with a fantasy caveman land.

Caveman land implies human nature without needing to make an argument for it. It is so far in the past that there is limited evidence, and most people you encounter aren't anthropologists. So you can justify all your unexamined assumptions about present society with an appeal to the caveman land.

Ironically, all you need to craft a fantasy caveman land is an imagination. "Picture hunter gatherers, sitting around a campfire, carving rocks into Pokemon cards and trading them." What a great story! Anything is possible in caveman land.