I have to disagree. I feel that recommending that a diabetic get 50-60% of their daily calories from carbs and then making absolutely no distinction between high glycemic carbs and lower glycemic carbs IS irresponsible, regardless of what the current dogma is. 50% of an 1,800 calorie diet from carbs equates to 225 grams of carb per day. This is supposed to help diabetics control their disease? It's only a minor decrease from the typical American diet today.
It's not a new idea that diabetics have a profound problem with carbohydrate metabolism. This was recongnized already in the 1930's and 1940's, if not sooner, and the diet of choice for diabetics before the advent of reliable injectible insulin and other antidiabetic drugs was restricted carb.
What changed? The development of antidiabetic medications that allowed diabetics to eat more carbs and still maintain their blood sugars. Was this a good thing? In many cases, yes. Some people (though not nearly as many as currently take them) need those medications to control their blood sugars even with proper dietary changes. BUT...it also produced recommendations for carb intake that pretty much ensure that a diabetic (at least a type 2 diabetic) will become dependent on medication of one type or another to control their disease instead of making dietary changes. That's not good.
The low fat dogma simply added to the problem by replacing fats with more carbs and simple sugars producing an epidemic of diabetes that has never been seen before and a population that is more obese than ever. How many more decades and countless studies will they need before they figure out that what they recommended is doing more harm than good?