I don't need to read the article you linked, because SOMEONE made up the term "Mexica", just like someone made up the term "Aztec" (and every other word ever).
The term is not eternal, not deemed by God (or Quetzalcoatl)...
Also there were a variety of peoples, to say "they called themselves Mexica" as if they were one people is actually dumbing it down, friend. They didn't even all speak the same language.
Dumbing down for people, indeed. It's all over your head, and I'm sorry