“Princess”? Bah! Celestia is THE QUEEN! She’s gentle and wise only in front of the cameras. Backstage, however, she order executions left and right and throw everypony who dont agree with her in the dungeon. Don’t agree with the pure principles of harmony? She will turn you into stone and put you in her garden. Chrysalys and her people? DEAD! Once they were thrown out of Equestria, she nuked them all with the power of the sun. Celsetia could easely fix some crisiss but she sent Twilight and Co to fix them because, as QUEEN, she dont have time for this bullshit. Even with TWO other princesses, she know she will remain unchallenged because she the fucking QUEEN. Yeah, she dont call herself “Queen” in public because her PR department advised her to. But in private, you better call Celestia QUEEN. Or else.  
Deal with it.