My take an the carb curb is this:
- His trying to give a basic guide line that covers most people ( adult people - with 'sit down' jobs)
- His readers are mostly adults, not growing teenagers that need plenty of good carbs to grow.
- He often says the carb ( good carbs) intake should match the level of activity - eg a high level of activity is done by professional athletes and growing teenagers ( just the growing bit is a high level of activity in my opinion - not counting movement)
So in that light, I don't have a problem with is carb curve guideline.