The discovery of wild grains and their subsequent cultivation eventually brought about the expansion of the human brain and a great increase of IQ, and we would still all be living paleolithic style if not for its consumption. Grain has been described by food philosophers as a "highly charged" food, which is why it produced a relatively quick increase in human intelligence.
Also, it is not for me to say if this further development of the human being is part of some great Divine or cosmic Plan - or if we "should" have stayed at the early stage of development of the people we now call "aboriginals". The cat's out of the bag and we have to live with it.
So, I wouldn't slag grains. I think that the Weston Price Foundation people have it right: that grains can be problematical if not properly prepared.
But it's meat you were talking about: every disease, illness, condition that I've seen in vegetarians I've also seen in meat eaters. It just isn't a simple meateater VS vegetarian debate. Same for raw vs cooked. Same for grains vs no-grains.