User blog comment:TheNewProtagonist/Episode 15: How many times can I say "shit just got real"?/@comment-918376-20131101011939/@comment-173.58.64.38-20131101033951

It's to show they're girly, not like the Power Rangers, who have predominantly male-like uniforms. Sailor Moon, Mermaid Melody, Wedding Peach DX, they all have girl characters who wear skirts and short shirts into battle. The point being made is to show that while they fight, they're still girly at heart.

It fits in with the "magical girl" realm anyways.