Why did Augustus refuse to be crowned emperor?

Answer 1

If the word "emperor" were part of the Roman vocabulary, Augustus would have refused it because it's meaning was too close to the meaning of king. During his reign, Octavian was known also as First Citizen and later added Caesar. He took the neutral title Augustus to avoid any suggestion of kingship - it was Julius Caesar's taking the Dictatorship-for-life which brought out the knives, so Octavian and his successors stayed well away from any absolute ruler title.

Incidentally, the term emperor was never used in Roman times. It is a word/title that we use today. The closest thing to the word that the Romans had was the title "imperator" which was an honorific voted by a general's troops after a victory.

Answer 2

Believe it or not, Augustus ruled within the republican structures created by the Ancient Romans that came before him. He did not claim to be emperor because he was not. To do so would have been anti-Roman.

It would be as if the American President became a supreme court justice, presided over Congress, and then declared himself a King.