That is very depressing to hear Snaplittledragon, I am not looking for a fight about vets, there are crap ones out there, but the majority I have known truly do have the animal`s best interests, rather than their wallets, at heart.
That is not strictly true about dogs and grains, way back when, dogs would have eaten the stomachs, intestines, bowels etc of their prey animals which would have contained partially digested grains, vegetables etc and which made it unnecessary for them to seek out such diet additions separately.
Of course dog food shouldnt be mostly vegetarian, I dont think anyone would say differently, some kibbles are rubbish, some raw diets dont contain the correct RDAs. My grip with judging by ingredients lists is that they can be deliberately misleading, as "fresh meat" allows them to include the water content in the meat %, whereas ground dried meat, for example, doesnt sound as good to consumers but does actually have more meat.
Or people are prepared to treat their dogs now, and optimise their health whereas they didn`t so much years ago and so many ailments went untreated?