Pretty much all the above arguments about lighter boats were raised when lighter(not nec. ultra light) modern sailing craft including multihulls came along. With sailing craft it has become apparent that light modern craft are safe and can be comfortable. I am not talking radical light but when comparing my previous J/44 at 24,000 lb to an equivalent older 44 boat at 50,000lb the ocean crossing abilities were very significant. If you spend two weeks less out in open water you are that much safer. If one's mind set is firmly in the camp of heavy is better than the NH should have a heavy steel hull and there are plenty of offshore boat builders who may agree since that's how they build. This type of difference of opinion can never be resolved. The hard numbers regarding passage times and fuel burn can be compared but things like comfort, and perception of build quality, and safety are often more subjective. As for plugs yes they can say a lot about a build but the thickness is not the key point. A thick plug with bad materials or poor laminate technique may be far inferior to a thin plug.
We're not a sailing group though and when it comes to power boats, the consumer has spoken over and over and while narrow and light is popular for high performance boats when it comes to trawler buyers and yacht buyers it's been soundly rejected. There is nothing new about the concept. Yes, if you want the most economical loop boat, just get a sail boat and remove the sails. But 99.9% of power boat owners do not want to spend a year or two looping on that boat.
People don't want the absolutely most fuel efficient streamlined boat, they want something in between. If they wanted that, they'd just put motors on kayaks and go.
You are right that if one wants more weight and a better crossing than NH they can go to steel. But steel comes with it's negatives and NH makes a good compromise. All boats are compromises. I'm personally not an NH fan, but I don't argue with the facts that they're very popular and their customers on the whole are extremely happy with them. And the NH customer is not about to switch to long, skinny and light. That isn't who that boat would even be targeting. It's real target is the sailor coming over to the dark side of power who appreciates the design and efficiency and doesn't mind the aspects of it that most traditional power boaters dislike.
Your perfect boat, eyshulman, is not one the majority of the market has interest in and has not yet ever been shown to have commercial viability. I do hope one day you're lucky enough to get one. But if I won one in a lottery tomorrow, it would be on the market to be sold the next day. Just we're all after different things.
Long, skinny and light is different to different people too. William Garden believed in the concepts but just applied them in different ways. For instance, most Westports are Garden designs and they'll all run 25 knots WOT and cruise at 20, from the just dropped 85' to the 164'. Of course, the 85' carries 3000 hp and consumes 80 gph at 20 knots and the 130' carries 5780 hp and consumes 130 gph at 20 knots. However, that is significantly better both performance and fuel wise than most other boats in that size range. By comparison a 100' Hatteras requires 5200 hp to run the same speeds as the 130' WP and consumes 150-160 gph doing it.
Most engineering concepts are not applied in their purest forms but used to improve boats that are in the market place and meet needs. In my previous work life our engineers developed the absolutely scientifically proven best bath towel ever. It dried better, was better for one's skin, and it would quickly dry out and no mildew or smell. Washed well and lasted three times as long as traditional towels. Only one problem Took it to a focus group and not a single person said they would ever buy one. The consensus, "It looked and felt odd." Who knows, it may resurface in 20 years. But the consumer speaks last and most powerfully.
