It's because it's just not attractive. It's only used by three kinds of people. Girls who can't get any better than a fatty guy, girls who married a guy who gained weight, and guys trying to write off their aging overweight body as muscle with fat over it and a beer gut. All three know they can do better. With fat chicks they think the men should come to them because that's how it works. If there's no men coming to them, the men must be broken, the system must be broken, there must be dams in the river.