Patrick:
It is hard to determine why more modern designs do not incorporate these design principles into their designs, however, I am not certain of the basis of your research into modern courses and their lack of these timeless features. Is your basis an assumption, an informal survey, a scientific survey and analysis? Have the modern designs received enough study to dismiss connections between them and classic designs, like the amount of research that has gone into the connections between the dead masters designs and the British Isles courses? If so and based upon this research you have reached this conclusion that there has been an interruption in the connections between the British Isles, and modern courses then it is a sad conclusion. Most strategic designs you have mentioned, and their recognition and use in course designs by the dead masters I think illustrate the brilliance of their expert analysis, contemplation, and execution in their new designs. These principles are probably timeless, or maybe a better way to describe them is that no one originated them, the principles have always been there for those who were willingly to receive them. You mention the 7th at NGLA, and I will say I have only walked the course twice, never played, and reviewed Bahto’s book regarding the hole, some of these principles of design are timeless, and in some way probably are included in the design of modern holes. How this came about on a modern design is interesting to consider. It could have been the original road hole or the NGLA design were direct inspirations, it also could have been that the modern architect stumbled upon these principles by just being on their land studying the terrain before them and through this face to face encounter and an active mind engaged in the moment the idea for a design came forth and it just so happens it is similar to the road hole or the 7th at NGLA, simply because they found inspiration from the land and because the strategic principle is timeless. Jefferson and the Greeks did not necessarily invent freedom and democracy, it is a timeless principle, maybe a divine principle that has always been present, or at least the possibilities have always been present since the earliest man appeared. It has always been present in the spirit of human kind, the spirit of the Earth, the holy spirit, however you want to term it, but it did take special, creative people to bring it forth for all to recognize, and people still come to under stand it more fully through their own introspection and experience and they may have never read a word about Jefferson or the Greeks. So, some credit should be given to modern design even if it does not specifically cite the old masters or the British Isles as inspiration because the modern design could very well reflect the same design principles through its own way. Some may be too quick to dismiss a modern design because it does not pay sufficient homage to the past. I recall a discussion with some one about a specific bunker style on a modern course and their immediate response was to inquire if Ross influenced that style. No, it just came to mind as the result of countless time spent contemplating land and strategy. If you speak of inspiration from something other than the old masters or the Isles people just flat turn you off, they do not want to hear what drives you if you do not have a dead master sitting in the passenger side with you.
This is all to say that your question is excellent and its implications are correct, more should be done in modern design to incorporate some of the principles you have cited to make golf more fun, but the architect must be allowed to discover these principles in their own way so that design comes more from internal inspiration and introspection. I think people whom pull design from within themselves, whom allow these design principles to brew within them and allow it to boil out from within sometimes in surprising and inspiring ways are far more interesting as compared to those that talk about what old master inspired them and how this hole they designed was inspired by this old course by this old dead master. Tell me what really grabbed your mind and your heart when you stood there on that raw land looking over the virgin terrain. Some one told me the other day that while setting up a volleyball net in their back yard they suddenly discovered their yard was just like a Flynn green, and they took a couple of their associates over to show them this magnificent Flynn green in their back yard. I did not know whether to laugh because it was a put on or to put my arm around them, hug them and tell them everything would be okay, they could beat this disease. Some of the implications from your question have resulted in the most ridiculous idolatry and rubbish that sometimes stains this website, and it has led to down right misrepresentation by some practicing designers.