I disagree completely. You have to take into account dietary thermogenesis, so it is not as simple as carbs that are not used gets stored as fat. Carbs get used as heat or energy and for it to be converted to fat you will have to overeat to a great extent. The exact figure is unclear although one study showed it would have to be around the 15g of carbs per kg of bodyweight for you to start gaining a small amount of weight from it.

It is true carbs will spike your insulin level, although this alone should not be a problem. The problem arises when we eat a lot of fat along with carbs, which prevents the carbohydrates from being efficiently absorbed, hence causing a high fasting insulin level (longterm aka T2D). We can't blame the carbs because if you ate a high carb diet (low in fat) your fasting insulin levels would be low. As we see in the Asian populations in the past who lived on mostly white rice, starches and fruit.