A stripper wears next to nothing prior to wearing nothing, and the entire purpose is to show as much of her naked body as possible before stripping. A fashion model wears next to nothing to show off the flimsy bits draped about her body. Nobody really cares about her anorexic frame, nor would anyone want to see her wearing nothing, because her elongated bones only serve to hang the flimsy bits on and parade them around the catwalk.
On a more general note: though there are women in the fashion business (fashion designers such as Jill Sander, Laura Biagiotti, Donna Karan, Vivian Wood, etc.), and their fashion is just as sexy if not more so than that of the male designers, fat old males still dominate just about every top level of society because we live in a patriarchal world, the fashion biz being no exception. (Footnote: Yves St.-Laurent may be a tattering old fogey, but he’s not fat, as far as I know; I quite like his style – I only wish I could afford it…)