Because models are idolized in this time. Because they come into view with only their looks, and sure they are nice, sometimes pretty hardworking people. But what for? They do not add anything to our progress. If they not slow it down because they participate in this business intended on keeping as many people as insecure as possible in order to keep them to buy things. You can take that attitude and say it about practically anything that has to do with aesthetics, which modeling would fall under. Models are needed to display fashion clothing if we're talking strictly fashion models. So they are useful obviously. A lot of models promote businesses depending on the type such as fashion, glamour, fitness or art for instance. Businesses add to our social structure.