We feed our dogs grain-free Orijen, which some say is too high in Protein, some say quite the contrary. The way I look at it..who cares what other people think in regard to what you feed your dog? lol As long as you're feeding whatever food is best for *your dog's* body, you're doing the right thing.
We feed grain-free because Brussels has issues with grains affecting his tear ducts and staining.
That being said, I don't believe grains found in nature (not processed junk) are bad for dogs, tbh. They're carnivores, which means they eat meat. Which means in nature, they also eat whatever their prey eats (many of which eat ..ahem..grains).
In any case, I say feed your dog what your dog seems to do the best on. Just like humans, no one dog is the same. Some dogs do much better on grain-enriched foods, while others cannot tolerate it whatsoever.
Bella loves Orijen and it is very good for her, BUT she also needs her i/d that we recently got. The fiber in that food helps to bulk up her poopies and make it much easier for her to go potty, instead of straining to push out protein-packed poopy. She needs both...Brussels does not (prime example of dogs being different).
Find what works best for your dog...not everyone else's.
"....and that's the truthpllbbbb" ~Edith Ann (Lily Tomlin)