well, see, from the parents point of view, they don't think their kid is entering "that stage" at that age. Well... the ten year old IS entering "that stage" at that age. Whether they're aware of it or not. Any bit of extra flesh they can see is a bonus. As for near-naked leaving less to the imagination, you're right and you're wrong. You would think that having a woman fully-clothed leaves more to the imagination and you're right, but the image of a half-naked girl spurs the mind on to greater heights. err... depths, I should say. Near-naked is like the embodiment of imagination.
Also, they're not just marketing it for kids. They slip in that extra expanse of flesh and they snag every drooling male, too. Personally I liked the games for the story lines and game play, so the extra flesh was a bonus.