Why, is not a question you get to ask. Why is up to the user. What one wishes to use Poser for, is that person's own business. Asking this gets you into the area of propaganda, and propaganda in its orginal sense at that. The mesh in the hip is too sparse to support much in the way of morphing. The area of the pubic bone may have enough to shape. In my estimation, the rest will require a prop. Someone is probably going to do this by merging the prop with the hip geometry. This will negate morphs, and mess up the texturing. Granted, DAZ' patch job on the replacement hip mapping looks a little strange, with the saw tooth border, but it is flat. I think the prop should just be that, a prop. It will work just as well.