I also agree that different dogs need different diets. Some dogs will do great on a premium kibble that will not do well at all for another dog who does best on a raw diet. I believe it is up to each owner to research food and then see what works best for their individual dogs.
I feed Blue Buffalo as well to my adult dogs. However, I have one dog with cholesterol pits on his corneas caused by fat in the diet. I have to keep him on low fat kibble, and Bil Jac senior has worked best for him. It does cause his coat to be excessively dry, but the extra oils in food to make his coat shine will also cause his cholesterol to increase and the sight ending pits to return.
I had another dog who had terrible allergic reactions to common proteins such as beef, chicken, lamb, etc. Every few years, I had to switch her food to another "novel" protein as she became allergic to the protein she had been eating. After going through chicken, beef, lamb, turkey and venison, I switched to Pro Plan's sensitive stomach recipe with salmon. I am NOT a fan of Purina products or Pro Plan and cringed when I did it. But it turned out to be the only food she tolerated for more than two years. She was on it for the last five years of her life and passed away from old age a year ago.
Different dogs need different diets to meet their individual nutrition needs. And, yes, the people have to be taken into account as well. A raw diet just isn't feasible for some people who travel extensively with their dogs. Also some people have very limited incomes and must find an inexpensive kibble or raw diet that will work for their dogs.
An "one size fits all" answer doesn't work when it comes to canine nutrition. :)