As someone who works out quite a bit, it is easy to view most of the population as "out of shape". How many people can do 20 push-ups if asked randomly or run a mile without stopping? I've seem lots of skinny people who have no muscle tone and smoke and take no meds. I don't see these people any differently than the fat people mentioned in the OP. They are just an easier target because of their appearance.
Either way, neither group is healthy or in shape and shouldn't be glorified. Less emphasis on body image and more on lifestyle changes is a better way to reach everyone.