I think the main purpose of the whining is to prevent such outfits from being sold to any tween girl, whether their own or not, due to the fact that they offend sensibilities by transgressing against accepted norms of propriety for girls. If most parents were sewing their own versions of these costumes in place of buying those manufactured by others and sold in stores, you could rest assured these whiny blogs would be modified accordingly to reflect that.

Btw, I never saw the adjectives "pissy" and "angry" combined into one word before via hyphenation. That was pretty interesting! :-)