I would LOVE to see these statements backed up by some actual data.
If by "nutritional value" you mean energy, then you are completely wrong. Grains have calories (aka energy, 4 cals per gram, the same as protein), therefore they have nutritional value. If you mean "nutritional value" in terms of vitamins/minerals, brown rice, for example, is a good source of B vitamins (thiamin and niacin), iron, phosphorus, manganese, zinc, and magnesium. It also contains unsaturated fats shown to help lower cholesterol.