[snapdangle]

When the only means of preserving your history is to speak it truthfully, that's what you do.

[irrational]

That might be the main difference. They would have considered the idea of "preserving your history" to be not worth considering. It didn't seem to be something they valued (at least in the sense we understand it).

[snapdangle]

That's entirely the cultural bias of treating other humans as savage and primitive and not listening to a word they say.

[irrational]

They were hardly primitive, they just valued things differently than we do. Having a different value system doesn't make them savages.