I certainly wouldn’t say it’s naive, simply not necessary. As Dr. Phinney and others point out, there is no known carbohydrate deficiency disease—in other words, the human body’s minimum daily requirement for carbohydrate is 0 g. By contrast, nine of the 20 constituent amino acids in human proteins must be present in our diet, because the body cannot make them. Likewise, we require a certain amount of polyunsaturated fat, because the body cannot make ω-3 and ω-6 fatty acids, either.
There are also indications that the body responds well to the absence of carbohydrate. For example, the high insulin level that accompanies a significant carbohydrate intake activates the expression of certain genes that turn off the body’s natural anti-oxidant mechanisms, and making it necessary to find dietary sources of Vitamin C, for example. Whereas the ketone body β-hydroxybutyrate acts to turn off the expression of these genes, reactivating our built-in anti-oxidant mechanisms, and making Vitamin C unnecessary. Fascinating, huh?