I would agree with this premise, depending on who is defining skinny. I know athletic women that are called a "skinny bitch" by people.
This is one of those "best of intentions" ideas that has a basis in, and quickly becomes about, political correctness. While I understand that people have become increasingly overweight and don't like being reminded of that, it doesn't change the fact that the majority of people find certain body types more attractive.
Even in the era of supposed "curvier women" (Marilyn Monroe timeframe), the average waist size of famous actresses, based on dresses they wore, was along the lines of 18 inches. Marilyn herself was tiny and they couldn't even find a manaquin small enough to show her dresses on.
Now, I would completely agree that Kate Moss skinny is, in fact, a problem, and I would definitely not want kids using her as a role model.