Does not change the facts that grains contain phytates, lectins and gluten all of which can and do cause issues.
Plus if you had done some research you would probably be aware that the current grain (wheat) that we grow today has only been created by genetic research in the 60' and 70's and that the grain people consumed thousands of years ago was very different to the grain we consume today. Modern wheat also contains gliadin which is an opiate, and I will let you research what it does to your opiate receptors in your brain.
For someone that micromanages their diet to the last gram you have not looked into what you eat too much based on your comments.
Plus you mention that humans have eaten grains for thousands of years, but fail to consider that evolution takes about one million years to adapt to changes like that.