If these civilizations were so strong, how come they didn't event firearms? I think I know the answer, but I want to hear what other people think.
The only iron in the cultures was from meteorites. The copper, silver, and gold they used weren't strong enough for guns.
Sulfur, saltpeter and charcoal were known but it's a fussy formula to make black powder.
When the Native Americans finally got guns from the newcomers they became totally dependent on the Europeans. The Native Americans didn't have the industrial base to repairs and replace the guns or to mine the lead and make gunpowder. Even by 19876 at the Battle of the Little Bighorn, muskets were often preferred as mismatched cartridges could be broken down to powder and lead that a musket could use.
Perhaps the biggest reason was culture. Both groups didn't encourage initiative or individuality. Leonardo Da Vinci would wouldn't have done well. Alchemy the basis for chemistry and gunpowder never developed.. While there was lots of warfare it wasn't the European type. In the Americas it was among warriors where one gained fame and prestige and was a rite of passage. Simply look at the elaborate dress of the warriors. There's more culture then practically. Counting coup was purely American (getting close to slap of tough an opponet. Killing or shooting them counted much less) In Europe fighting was intended to kill. With the Aztecs it was to obtain prisoners for sacrifice.
Finally, both empires were relatively recent and had rolled over their opponents. In Europe there were many small states that were constantly fighting with each other and seeking to obtain an advantage. That encouraged innovation and technology.
Just the way it was! They didn't have the wheel either. Anyway, the use of firearms was only just getting into it's stride in China and the West at the time the Aztecs were being conquered. You may as well ask why the Arabs didn't invent gunpowder, or why the Chinese, or the Romans didn't invent a numerical system as simple and the one invented in India.
Clearly the Europeans who had the benefit of gaining technology from all of Asia and Africa as well, were more advanced. Perhaps the Aztecs would have eventually invented them but the Europeans conquered them first. Europeans developed shipping before Aztecs had any hope of inventing those things.
Uh,only ONE civilizations invented explosives: Chinese.
So you should also ask "Why didn't Europeans or Africans also discover explosives" rather than targetting those two civilizations.
They WERE strong. There's no reason to assume every strong civilization would invent firearms.
The concept wasn't in their minds yet. It was probably too early for them to discover this.