It's not terrible, it's just pointless. Fat people know they're fat; people who self harm know they self harm and they know it's not ideal.
Merely saying "stop doing that" does nothing ot help them stop.
A good doctor understands that an eating disorder is part of a complex, intertwined and difficult to understand network of causes and effects. Helping the patient understand the complexity of the situation is often the first step towards a permanent solution.
Many don't. Or they don't blame overeating. It's always "genetics" or "metabolism". Not just plain old overeating.
I disagree with one point. It puts things into their control, rather than out of their control.
If the doctor says you're fat because your metabolism is low, or you're big boned, you can shrug it off and say "Well, there's nothing I can do about it, might as well not try."
If the doctor says you're fat because you eat too much food, you can do the same thing, but then at least the ball is in your court. You are fat because of your actions, and it's theoretically possible to change your actions, but it's definitely not possible to change your genetics or metabolism.
How terrible would it be to have a doctor tell you to stop smoking? Or to stop drinking? Or stop abusing drugs? Or to stop cutting yourself? It's all self destructive behavior just like overeating.
Has our culture really become so sensitive that it's now no longer acceptable for a doctor to tell you when you're being unhealthy and contributing to your own demise????