In a person who is not a diabetic, insulin is produced by the body to deal with any carbohydrate eaten and the blood glucose level is maintained at a steady level by releases of glucagon and insulin, in response to tiny changes. Only 'fine-tuning' is required, ie. tiny adjustments. In a diabetic on MDI, a ''job lot' of insulin is injected all at once to cover the carbohydrate in a meal. Most of the time this more or less works, or none of us would be here, but it's not how our bodies were designed to work.
The glucagon produced naturally deals with small drops in blood sugar level in every normal person, but no non-diabetic wakes up feeling the way we do after a over-night hypo ! In this situation, the liver is likely to have been forced to produce glucose for several hours, to cover the continued action of the insulin. In my experience, the longer we have experienced low blood glucise levels, the worse we feel afterwards.
A dramatic drop in glucose level overnight can happen and is life-threatening , because the individual concerned is not eating and unaware of what is happening. I have read that if you have had an unusually active day, you may be liable to abrupt drops in blood glucose for more than 24 hrs.afterwards, which will always include a period of sleep. I can confirm this from personal experience. I know myself that after a series of exams finished I would always have an overnight hypo, as a reaction to the sudden ending of a period of stress. In addition, some of us are more sensitive to insulin than others. Our insulin requirements change over time and other hormones affect them. We are not all the same, we eat differently and live different lives, with different amounts of physical activity. We take different amounts of different insulins, (at different times) that have different profiles. Because of all of this, I don't believe anyone should regard a hypo during the night as less than dangerous. We cannot know what the future consequences of such advice will be.