I am disappointed in Celestia · 3:29pm May 10th, 2014
A millennium ago, Princess Celestia had to banish her sister to the moon. And for a thousand years, she regretted that it had come to that. How much better it would have been had she reacted to Luna's jealousy when it first started to appear, before it carved a rift between the two of them, before there was nothing to do but let it fester and hope that Luna could guide herself off of her dark path. If only preventative action had been taken in time, the sisters would never have been separated at all.
So, naturally, when a similar problem could be arising, Celestia would take prompt measures to solve it. If, for example, the newest princess were feeling unappreciated because she has no royal duties beyond the purely ceremonial, Celestia would of course give her . . . vague platitudes about how she'll find her destiny in time. Yeah, that'll accomplish a lot.
Sure, Twilight loves and respects Celestia and would never do anything to hurt her. But surely Luna felt the same way about her big sister when they first began ruling together, and look how that turned out. And sure, Twilight is the Princess of Friendship now (which is weird because I thought that was what she's been since last February) and feels useful, but there is no way Celestia could know that a crisis was about to arise that would spur Twilight and friends to finally open the box and unlock their super magical filly transformation friendship powers and create a castle and all that. She just got lucky. And Celestia of all ponies should not be relying on luck in a situation like this.
On a related note, I commend Luna's self-control in not saying anything along the lines of "be grateful that you at least get a lack of responsibility to go along with your lack of appreciation, you whiny nag."