Commenter upthread said they "did not invent it quickly enough", as you quoted, which is not the same thing as "did not invent it". They just meant that the Native Americans invented it later than the Europeans did, such that the natives had less time to develop advanced (military) technology.

Do you really think that a process that was discovered repeatedly throughout the world was thousands of years behind on one side?

Edit: We're talking ~10k years difference.