Would you call a diet that contains 75-150 grams of carbohydrate a low-carb diet? If so, then you’re not alone. I think most people, including the vast majority of nutritionists and dietitians, would answer yes to that question.
We humans tend to base our understanding of what is natural and normal on what we can see and hear. Today, the vast majority of people eat a diet that is high in grains and sugary foods. At least this is the case in westernized societies, where pizza, bread, pasta, chocolate, and many other carbohydrate-heavy foods are routinely consumed by a substantial part of the population.