[Clara Lou]

You're dwelling on one aspect. When the Spaniards arrived, the Aztec capital was cleaner than any European city ever dreamed of being. The streets were paved, there was no stench of roadside sewage. There was a zoo. The Spaniards marveled at the city and then later destroyed it.

[NeoCaveman]

The streets were paved, there was no stench of roadside sewage. There was a zoo.

And human sacrifice too.

[Welsh Rabbit]

When the Spaniards arrived, the Aztec capital was cleaner than any European city ever dreamed of being.

That's not saying a lot....

[Restorer]

The Spaniards marveled at the city and then later destroyed it.

True. But not because they wanted to. The Aztecs fought so tenaciously that the Spanish and their allies were forced to destroy the city in order to conquer it.