I agree, the vets don't seem to know a thing about food. I feed my cats premium food (California Natural & Wyson dry). I asked the vet about them & she said she's never heard of them! Needless to say I was really surprised. I talked to the owner's of the pet store I go to (they sell only premium brands & know a lot about nutrition) They said vets only take 1 course in nutrtion in school. don't know if this is true or not.
Again , like your 'people' doc, there is no way they can specialize in every aspect. That is what specialists are for.
And it's not across the board either. Some vets take a special interest in nutrition; some are less in tune with thinking outside the box. Same with a pediatrician or family practitioner.
When I go to the vets', sure I'd love them to know EVERYTHING. But most importantly, I want their diagnostic skills TOP NOTCH. I want a vet that knows what to look for and how to treat a condition, and has compassion and empathy for us and with our pets.
If they aren't as up with latest foods, I can forgive that; but I would expect a good vet to research it if a 'case' warranted it, and not just toss me the textbook answer, but instead LISTEN to my concerns and work with me.