I have to say....

Ketosis is not just a state you are in when you are starving. It's a state you are in whenever you are burning fat. Fat metabolism produces ketones as a byproduct of that metabolism. So unless you are willing to say that all diets where fat is burned (and that would pretty much include all diets for the purpose of weight loss) are unhealthy, you might want to rethink your position on the danger of ketosis.
Furthermore, our ancestors that lived in hunter/gatherer societies lived in a state of ketosis for several months out of every year and did quite well on it. Inuits that follow a traditional Inuit diet still live in that state for many months of the year and have a much lower rate of disease then than their higher carb counterparts.
Being in ketosis does not mean that you are starving, although one could argue that all diets that produce weight loss through a negative caloric balance are simply a controlled state of starvation. Is this dangerous or desired for weight loss? If it's dangerous, then all diets that produce weight loss through "starvation" should be condemned equally. Personally, I get more than enough calories daily to support my basal metabolic functions (between 1,500 and 1,800 daily) and have still managed to lose 75 pounds over an 18 month period (no...my weight loss did not stop after a few weeks).
Finally, I have to disagree with your statement that a ketogenic diet can only benefit certain rare disorders. I wouldn't consider diabetes, especially in it's near-epidemic proportions, a rare disorder and low carb diets are certainly helpful in controlling that disease as well as insulin resistance.