Earlier quoted context omitted.
She may be correct. The 70% ratio that many Americans eat may not be great, but 30% or 40% carbs seems about right for me. I see the no carb movement much like the no fat movement of the 80s.
Except for the fact that carbs are the only macronutrient that are not essential and can be completely synthesized by the body via gluconeogenesis. There are essential amino acids that need to be sourced via food (protein). There are essential fatty acids that need to be sourced via food (fat). There are no essential carbs.
Some other aspects of carbs seem to be not fully investigated, such as the effect of dietary fiber's role in nutrition. While not "essential" (http://jandonline.org/article/S2212-2672(15)01743-8/abstract) it seems to play a mostly positive role. (If only to prevent constipation...)
At this time, I'd think "fad" of any ketogenic diet advocate that has little vegetable consumption. But as the first link states, "most of the current low-carbohydrate, weight-reducing diets advocate the consumption of low-carbohydrate vegetables". "Eat more veggies" has been a mantra of dietary advice for a while. :)