Is part of what we're talking about when we say "natural" really the difference between convex versus concave design?
Once again, I'll admit that I'm merely stating observations based on pictures, but I'll tell you what I've observed.
It seems to me that in most classic designs, the fairways and greens occupy the "high points" with the land naturally falling from those preferred areas.
In much of modern design, whether through the use of mounding, shaping, or simply routing holes through the "valleys" and other low points, it appears that many of the courses are built up around the edges. Usually, the tee occupies a high point, but the fairway sits in a concave valley, and the green often does the same.
Then I look at a hole like 11 at Shinnecock which seems so easy to build, and wonder why so few holes of that quality are built today. I look at the elegant simplicity of the green complexes of Garden City; mere extensions of the fairway and surrounding terrain really, and am perplexed why we get so ridiculously fussy in building some type of "green complex" with multiple tiers sitting among mounding and amoeba-shaped bunkers.
Isn't this fact really the secret of Donald Ross and many others? When we say that Ross found the "high spots" for tees and greens, aren't we also saying that he designed courses that were convex as opposed to concave? Isn't this exactly why they are so exacting? A less than perfect shot tends to drift further from the target, pure and simple.
I might be oversimplifying here, but when I look at the pictures of East Hampton, I see more of Garden City than Wade Hampton, to use a popular, well-regarded modern comparison.