What you say is true. I didn't truly resolve my gastrointestinal issues until I took sugar, and all glucose producing products out of my diet.
The proof is out there if only people would open their minds and study human physiology. We are omnivores that CAN eat complex carbs. But glucose does nothing in our bodies that is useful. Just because we can eat carbs, doesn't mean we should for our overall health.
Our big brains have led us to this. It would be much easier to be a goat.