There's a large middle ground here that tends to get ignored by the 'metabolic advantage' folks, who are incorrect to begin with. It's always either-or for them, when in fact, individual carbohydrate demands vary widely. For some folks, low-carb is warranted. For others, it isn't. It always amazes me how hard that concept is to grasp for low-carb absolutists.
I have always said that there is a huge psychological component to this industry. Seriously which sounds cooler: "I just eat a balanced diet" or "I am on a low carbohydrate cyclical ketogenic diet"?