Because when carbohydrates were scarce they were a good thing--eating fruit in its season, munching on wild grains in their season is a nutritional bonanza. Even as recently as 200 years ago, fruit was not as super sweet and abundant as it is today. The genetic makeup of grains was not so altered (yes, I know through hybridization, not GMO) as to be unrecognizable to our systems.If there is a God, and she/he cared about our health, then why did he/she make sugars and carbs taste so good. I always eat desserts first because life is uncertain. If I was just finishing my lima beans when the giant meteorite smashed into earth killing us all instantly my last thought would be of the dessert still waiting to be eaten !
Eating a lot of fruit every day and sugar and grains constantly is a nutritional disaster that's Monsanto's creation, not G-d's.