This is true. The vast majority of Americans do not eat sufficient fruit and vegetables. This 2015 CDC study [1] concluded that only 13.1% of the population consumes enough fruit, and only 8.9% eat enough veggies.
> It's quite silly to claim that 2000kcal of legume carbohydrate (more than 300 grams of carbs) will alter my hormones or metabolism in a negative way, so demonizing a macronutrient is bad science.
Nobody claims that. You obviously haven't read the article.
The excess of carbohydrates in today's diets doesn't come from fruit and vegetables (as [1] clearly shows), but from added sugar and refined grains. The article explains the critical role a chronically high level of insulin in the bloodstream plays in throwing the body's metabolic processes out of balance, leading to both obesity and type-2 diabetes.