The thing about crackpots with wildly unsubstantiated self-aggrandizing anthropological theories is that they often wield disproportionate power and influence. Take the Mormon church for example: they believe Native Americans were white Jews who were cursed with dark skin and it was god's will they be wiped out by European settlers. It's horrifically racist and there's zero evidence to support the origin story. And yet, the church holds over $100 billion in their investment portfolio alone and nearly had one of their own elected as US president. It's hard to laugh at.
Religion fundamentalists the world over very angrily push their myths as literal facts, and often politicians have to at least somewhat indulge them.
While multiple US examples are probably well known here, I’d like to suggest one from India from circa 2008, the controversy over the Sethusamudram Shipping Canal.
India wanted to dig a “canal” (more like dredge a shipping channel) in the waters between India and Sri Lanka. Religious fundamentalists opposed this because it would involve cutting a natural rock formation. What so special about these rocks? Well they were placed there by Lord Ram and his army of monkeys as chronicled in the Ramayana.