Baggy clothing is a "gangsta" thing. Gang members like the look because it allows them to conceal weapons without it showing. They like non-gangstas adopting the look because it makes it more difficult for the cops to tell who's who
I understand the origin of the baggy clothing for boys. My comment was meant to describe the contrast between how girls are walking school halls, vs how boys are.
Girls are the aggressors these days, and boys are the maligned, in so many ways. Just part of the destruction of the family - the foundation of society.