Let me repeat: There are zero (0) medical professionals advocating for a high sugar diet. The "high carb" part of the recommended diet is meant to come from vegetables and whole grains (which contain a fair amount of fiber).
There isn't any evidence I'm aware of showing people eating a calorically balanced, low fat, high carb, low sugar, moderate fiber, micronutritionally balanced diet and having diabetes. I understand that's more complex that saying "low fat/high carb" but again, there aren't doctors out there recommending cutting out fats and subsisting on sugar. So yes, it's a complete and total straw man, but when you only consider large macronutrient groups and ignore the rest of nutrition it's easy to see why that seems ignorable.