These are interesting threads for me because people assume too much.
I spent quite a bit of time studying the first two sites mentioned- Old Head for the original design, and Sandpines for a potential remodel - and I couldn't come up with anything much better than what's there, assuming you can't cut and fill along the coastline.
Sometimes, the site LOOKS good but there just isn't a really great solution to the puzzle. Or maybe I'm just not smart enough to see it, but somebody else will, someday.
So for me, wasted sites are more a matter of inferior shaping and construction work. That covers the whole range from Eddie Hackett at Carne (not enough money or shaping talent) to Perry Dye (too much money and ambition), and everybody in between who couldn't leave well enough alone.