That's a bit too harsh, and I spent a couple weeks living with the Hadza at one point. Even went honey-gathering with them up into a Baobab tree, although I was too scared to stick my hand in. They live in the African savannah, which is where humankind first evolved. Olduvai Gorge, where some of the oldest hominid fossils have been found, is basically next door to the Hadza. So while yes, Intuits are adapted to "extreme" conditions, the Hadza are living in the most "native human" conditions possible. It is anything but marginal, as there has been no evidence or history of famine ever in the Hadza people.
It is true that the area is ill-suited for agriculture, which is why the Hadza have remained, but agriculture is a very recent invention in evolutionary terms. That doesn't make the savannah "marginal". Also, the idea that you're not particularly closely related to the Hadza is obviously false, since we all share an ancestry with the original sub-Saharan hominids. If you're of European descent, for example, you share more with the Hadza than you do with those of East Asian descent -- as they also share more with the Hadza than they would with you.
You're correct in that this might not have much applicability to a modern diet, but it is valuable in puncturing myths such as the idea that "paleo" people never ate anything high in sugar. I do personally wonder if things like honey were common worldwide, though, whether it's berries or saps or syrups or similar.