Vet recommended food....selling snakeoil?

[Purpledomino]

Okay, today a friend asked if the Purina Veterinarian Diets were good food for her new puppy. Apparantly her vet yesterday gave her the whole monologue she had memorized from the Purina supplier, and sold her a bag of expensive puppy kibble. I looked at the ingredient list, and told her that to my knowledge, she can do much better in feeding her pup, as it contains a whole lot of crap...corn, animal digest, etc. Just out of curiousity, I just checked out the veterinarian diet website, and was shocked at the ingredient lists on the food that these vets are recommending. This one is for canine maintenance, can't find a whole lot of anything in there that is any good. I just cannot wrap my head around how a skilled professional could recommend this....any thoughts?

Purina Veterinary Diet (DCO) Ingredients, dry:
Whole grain corn, dried beet pulp*, poultry by-product meal, corn gluten meal, barley, animal fat preserved with mixed-tocopherols (form of Vitamin E), pea fiber, dicalcium phosphate, dried whey, potassium chloride, fish oil, animal digest, salt, calcium carbonate, L-Lysine monohydrochloride, choline chloride, Vitamin E supplement, zinc sulfate, ferrous sulfate, niacin, manganese sulfate, Vitamin A supplement, calcium pantothenate, thiamine mononitrate, copper sulfate, riboflavin supplement, Vitamin B-12 supplement, pyridoxine hydrochloride, folic acid, Vitamin D-3 supplement, calcium iodate, biotin, menadione sodium bisulfite complex (source of Vitamin K activity), sodium selenite.