Bioware, why? Just why? I no get pwetties?
You mean! 
In all seriousness though, this sucks. Even if animating a dress was that problematic, they could have come up with something more feminine than that! You also shouldn't be wearing the same thing as other members of the Inquisition because you are the Inquisitor! You should stand out from the others because you are the one in charge. Not to mention, the social travesty that is showing up to an Orlesian ball in....that. *shudders* It's an insult. Just toss your drink in the face of everyone else there! How dare you have the audacity to undermine the importance of such an event with your complete lack of respect?! What the frack?!
I feel especially sorry for Leliana. Poor thing would have loved to dress up for this, and they made her go to such an elegant event in drab. Such an embarrassment. She'll never get to have pretty feet again. I'ma hafta buy her the prettiest shoes I can find to make up for it. 
Just imagine if you coulda taken Leliana and Vivienne to this, both decked out with the fanciest pwetties they could get their lovely hands on. If your Inquisitor was also female, coulda been the best girls' night out ever! And you woulda all been so fab! If you're Inquisitor was male, you'd get to arrive with the two loveliest ladies at the ball.
'Tis a win-win is it not?