There's another component to all of this, and that's psychology. There are people who are anorexic/bulimic and it's a horrible affliction. There are also people on the other end who compulsively overeat, usually to cope with some kind of trauma or as a reaction to anxiety. Or just because they've been fed one way since they were children, and habits are really difficult to break.
Distinguishing those people from the people who can just decide to make it better is probably impossible.
So I see some validity to all approaches.
The problem with treating it as purely a medical issue though is that, by doing that, society is being more permissive of the poor decisions people make. People who can choose to eat better and improve their health that way might never find that out, if they're just told it's all medical and we're dust in the wind.
The problem with treating it entirely as a choice is your prescription becomes punitive toward people who genuinely can't control themselves.
So I think the right approach is a balance between the two. Having said that, I think the current climate favors the dust in the wind hypothesis too heavily, and I think a lot of people are hampered and harmed by a complete lack of criticism and concern as they make and keep themselves obese.