I was completely against the AC72's for every reason you mentioned but have changed my mind and at this time feel it's good for the sport and more importantly for the advances in technology these new machines are generating.
All that carbon fiber technology, mathematics, design and teamwork pushing the bounds of human endurance. All there is is change. I think this is a good one for sailing. Who knows, we might get something as monumental as Velcro out of it. A bit of a joke but it's in all honesty. The advances made by the super rich for fun and games in creating these amazing machines could very well become used in products by everyone.
I also agree with you that a lot has been lost in the process. Perhaps we need another race kind of like the beginning years of the Transpac. Every other year the boats would change. One year it was mono hulls, the next year it was cats and so on. Perhaps it would work for the Americas Cup.