Mmmm.........well that's not true, I'm a firm believer in doing what works best for the individual.
I really couldn't care less what diet someone follows as long it works for them, the only problem I would have (and this goes for any diet ) is when someone shouts it out loud that it's the only way and will not accept any other views, I've always advocated some reduction of carbs in the diet and eat a good third less than the RDA, I wouldn't personally want to go Ultra low-carb but respect that some have no other choice.
As you say there's ''no one size fits all'' and that has always been the case on the forum in my time here over the last 6 years, hope that clarifies matters for you oldgraymare