I guess what I'm saying is that nourishment can come from anything that works for your pup and is within the appropriate nutritional guidelines -- whether that's chicken meal or raw, organic, pasture raised, heirloom ostrich with a first and last name. I would feed ProPlan forever if I could because I know it works beautifully for many, many dogs and even got one of my pups through puppyhood successfully before he developed an allergy, which frankly has not gone away with the new very premium food but I'm madly in love with feeding two dogs one food and it's working for him so I'm going to choose the extra cost over lack of convenience. Small poops and fewer farts are a personal preference.
My dogs have all grown into healthy adults and I've never (knock on wood) lost one before the age of 16 or had any illnesses or injuries that were not injury or old age related, which I can count on one hand. I fed what was premium at the time but a grocery store food now. My current adult dog with great bloodlines and who's been on premium, holistic, human grade food his whole life is the one I've had the most health issues with, which hasn't been much but certainly more so than all the others.
My dogs' health, well-being, and longevity are of the utmost importance to me and there are many excellent breeders, pet owners, competitors, judges, trainers, etc. who feel the same and feed foods that are nutritionally complete but not holistic, human grade, or considered ultra premium. At the end of the day it's about personal beliefs, preferences, and experience. I certainly would not judge someone for what their dog eats unless it's not working for their dog and they refuse to change it.