The modern wheat is a product of a lot of breeding, just like we do with dogs. Because of it it's pretty different from anything you can find in nature.

Wild varieties of wheat doesn't have nearly as much gluten, and the higher concentration results in a lot more children (myself being one of them) reacting to the protein with an immune disorder(celiac disease).

So you can't just say "sugar bad, flour good" as if it was a binary decision. Everything has consequences on different levels.