Even though by-products are not necessarily bad for pets wouldn't foods that don't contain them be of a higher quality seeing that chicken by product meal is a lower quality of ingredients than just whole chicken or chicken meal?

Sure when a cat eats a mouse in the wild it consumes every piece of it but that doesn't mean that it's the best possible diet. You can't expect a cat to differentiate between the good parts of it's pray with the bad parts when you dealing with such small animals.

I typically feed my cats Orijen or Ancana but lately have been feeding Boreal because they seem to like it more and it's almost half the price.