I don't question that people that have lived with and for psychedelics their whole lives, and may come from at least a few generations of people doing so, for sure know a thing or two about the plants they use and the spaces those plants lead to. However, I would caution about turning that into the "ancient traditions" trope, unless it's "ancient" in the sense that some things are "ancient" in the US (100-200 years).
Clearly, the descendants of the Mayan people aren't living in societies that resemble much the societies of their ancestors a thousand years ago, for the better and for the worse. They live in societies part of the current, global techno-industrial society, even if they have managed to keep some remains of their traditions and old ways of life alive. And while I think that the Neolithic was a disaster for humanity and the so-called "discovery" of America was a disaster for the people living there, it's convenient to not forget that many societies there, particularly the more advanced ones (like the Mayans) were deeply unequal and violent societies. I don't consider a tragedy that traditions such as human sacrifice died out. The Mayan civilization is also a civilization that collapsed more than once, they seemed to be as "in balance" with their environment as Sumerians were (which is to say, not much, but still undoubtedly more than our current global system).
To make a comparison, a hundred years ago (or even just 50 in some regions) many rural areas in Europe still preserved many old ways of living, practices, and beliefs. But to have considered their folk healers and midwives as "Celts" (for example) and pretend that their beliefs and those of the ancient peoples they still preserve some traditions of are the same would have been preposterous. I don't really see any difference, in many ways rural Europeans of a hundred years ago were much more culturally shielded from the then-expanding techno-industrial system than current rural Mexicans (as there was no TV, no Internet, etc.).
So, I think it's important to listen to what people who do have a tradition of psychedelics use think about the expansion of its use throughout the world, but in my opinion it's also important to not idealize them, nor romanticize or absolutize their (likely recent, by historical terms) traditions.
This being said, how I interpret
is not as "they think all Westerners are too arrogant to receive and learn", but as that they think Western culture is too arrogant to receive and learn and thus they have no interest in "contributing" to it. That is, the point is about the culture and not about individuals belonging to it. Which, with the caveat above (it's not like they are not influenced by the so-called Western culture), I agree with.
Edit: also, it's clear that they don't think that all Westerners are too arrogant to receive and learned, as the OP is a Westerner that has been learning from them.