Ok but, the only reason you would care about getting energy super efficiently/quickly is if you're an athlete. Also while glucose is certainly easier to burn, I've seen evidence that ketones are actually a better source of energy. Since we have an obesity epidemic, and the vast majority of (fat) people are on the diet you're proposing, I would suggest that energy efficiency is not exactly a high priority for most people. If we know that carbohydrates will cause weight gain (not just in humans, but in animals too -- there's a reason why they feed cattle grain and not grass), and we know that the biggest health problem we have right now is obesity, suggesting that people should eat a lot of carbohydrates seems like terrible advice.

And if you're going to suggest that the solution there is to decrease caloric intake, I also think that's bad advice. We know, from type 1 diabetes, that your body doesn't store fat if insulin isn't present. Certain foods have a much stronger insulin response than others, and not surprisingly carbohydrates have a much stronger insulin response than fats. IE, the notion that all calories are equal is not supportable by the scientific evidence. So if the culprit is insulin response, it would make much more sense to adjust what you eat and when you eat it, instead of measuring a number (calories) that isn't that useful anyway.