Must every film he makes be spiritual? Clearly, he's making the films he has the freedom to make, from material that interests him.
Not at all... More power to him for doing whatever he wants. But if his Aztec movie is just a small, modestly profitable movie of no great social significance, it isn't an example of him wielding the massive power he created for himself. Nor does it account for what he's doing with the couple hundred million dollars he made.
On the other hand, who knows?... It's not like in 2001 I would have guessed that a dead-language passion play would gross $380 million in the US alone. (OK, almost dead... I know there are some villages that still speak Aramaic.) Maybe he HAS got the next Titanic.