Honestly it looks like all the resources went into male characters, the hairstyles, the cutscene animations, the slouch on the throne, the dance with the grand-duchess (which is why I suspect we're forced to wear pants). We need a bigger budget for female characters tbh.
The inquisitor isn't some woman born in the middle of an orlaisian ball. Despite the human backstory being nobility, all females of all races include either a very aggressive or oppressive history. The inquisitor starts in this story being very familiar with the concept of being a soldier, spy, or rebel. It's easy to believe that the inquisitor does not develop very feminine personality traits such as the attraction to pretty dresses and sitting in a powerful way woman would.
The inquisitor will act as a soldier should, proper posture and efficient clothing that does not hinder movement.
The dance with the duchess shows a very "manly" position because you are leading and dominating the movements of the dance. Every dance has a "dominating" partner and a "submissive" partner. Someone has to lead the way. There are many examples of women doing this in dance routines.
But hey, you could say I'm speaking from a place of ignorance considering I am a man. I always felt weird having fem-shep run around her ship in a dress or having too much make-up on. I would feel the same with my female Inquisitor. I hope the guys at nexus are getting good progress with the mod tool. It would be a nice touch for people who prefer the dresses.