This group lived outside of governance for 2 millennia and don't seem to have what you call "human nature". The fact is, our nature is partially "human nature" and partially a product of our environment. No one knows how much those two things contribute so you can't say "X is human nature". We don't really know and it's not easy to test. But capitalism doesn't exist everywhere and doesn't spontaneously pop up everywhere. What is true, however, is that capitalism seems to rely on continuous growth so they eventually encroach on non-capitalists and "convert" them.