Seriously, what kind of "Oh so powerful almost Physical Goddess" ruler let's the obvious villain monologue for almost 3 minutes before doing anything?
Same reason any other smart ruler would do that. Make sure everypony in the room hears the villain give a brief but detailed summary of their motives, plans, methods, and source of power. That way if your sledgehammer approach falls through due to the villain having sapped a bit more power than you expected (or apparently than Chrysalis expected — she herself seemed a bit surprised that she overpowered Celestia), you're not the only one with enough information to try a Hail Mary.
And I greatly enjoy the theory that Luna was absent because she was playing sentry at the tower when the shield broke, then moved right in the thick of Canterlot tearing the shit out of half the changeling army. If the camera panned 90 degrees further right during the fight sequence, you would've seen Michael Bay style explosions.
I still don't get why there are 3 princesses, yet only 1 seems to govern.
Cadence is visibly much, much younger, and Luna's spent a thousand years absent and the most recent year playing catch-up (and possibly therapy).
What's the deal with Cadence, by the way? She's supposed to be a princess too, but as far as I can tell her special power is slipping magical roofies.
That's hardly on the same level of moving the sun or the moon.
You can move the sun and the moon, but ultimately it's love that makes the world go round.
...sorry, I had to do that.
edited 1st May '12 4:33:14 PM by Pykrete