The biggest problem with these types of theories (e.g. Paleo diet, grazing, micro-eating etc.) is that there is no way to test against a placebo, for obvious reasons. So it is really impossible to completely test the theory scientifically.
This shows a misunderstanding of what science is about. You can set up control groups, that use different eating methods, but consuming the same amount of calories (and micro nutrients, etc.) over a given period of time. In some settings, double-blind experiments (with placebos) are indeed "better"; but it is not required to get scientifically valid results.
Of course it's just air, there's no such thing as a silver bullet diet. Health and longevity depends on so much more than just diet that there will never be such a thing.
But still, since there's money to be made by selling dummies miracle diets, there are some to sell. And since they can't sell the real thing because it can't be made, they do what they can to convince the customers that it is. Among other marketing tricks, pervert science so it looks like their snake oil is based on something more than just the will to make money from gullible people.
There might be some good science in the nutrition field. Sadly, it's drowned in a sea of wishful thinking, bad science and plain charlatanry...