Scratch should have a label too...listing ingredients and nutrition levels.
Yes. But those levels will be different from brand to brand making blanket statements problematic.
It's like someone saying "layer feed is lower in protein". Generally, yes, but there is a feed labeled as "layer" available to me that is 18% protein. That's as high as some of the grower or breeder feeds that people recommend when suggesting to boost protein intake. During molt someone recommended that I feed a particular product for the extra protein since all I was feeding was "layer". It was 18% protein, the same as I was feeding.
Regardless, scratch doesn't have "no nutritive value" as was stated. Neither should one make blanket statements as to the nutritive value of any feed item. Generalizations are fine, as long as it's made clear that is what they are.