In my case I could, in fact, teach my gastro specialist a few things about my supposed 'rare' disease but he already knows it all. If I were to follow his advice I'd be in worse shape. Just a fact and I'm not alone. Gluten is really messing people up. My GP was the best...came to see me every single day I was in hospital even though there wasn't a thing he could do for me. When the kidney doctor said my kidneys had quit and I'd have to have dialysis I said "no way am I living like that"...not going to happen...my GP, who knows me, said he knew I was going to completely recover. He and I were the only ones who knew that I'd make a full recovery and while I know it could have ended differently I really appreciated his support. He listens to me.
I don't think anyone is saying doctors should be blamed for peoples health just that they should learn to listen to their patients with an open mind and be open to new information.