I guess I don't have the definite answer for that.
If I were to take a guess, my best effort would be that in a universe where dragons exist and people can shoot fireballs from their fingertips it wouldn't be unreasonable to also include the idea that sheer magnetism and physical attraction works as a personal protective shield, just as well as physical armor but less heavy and chafing?
The Wilderlands of High Fantasy d20 supplement did that, actually. The amazons had 'amazon armor' that distracted people because it was skimpy but still gave good AC bonuses. Not sure if that was in the original Judges' Guild supplement.