> What explains the mutability of Marco Polo’s cities? A quarter of the way through the tales we learn that Marco Polo has no knowledge of Asian languages.
That's not it, I think. It's the fact that Marco Polo is bullshitting, and Kublai Khan knows it, and does not care. The whole point is that this guy is a borderline fraud, weaving tall tales, but no one cares because the stories are good. Its a comedic absurdist view, a mirror held up to fiction, basically asking, "who cares?"