Let's face it, boaters are a little less than 5% of the general population, and performance boaters are perhaps 1% of that. If you eliminate the "wow" factor - the handful of boats that really make one say "holy sh--, did you see that!" - and codify the notion that there must be 50 or 100 identical watered-down 'practical' race boats on a given course, I'm afraid it won't work. Don't get me wrong they're all fine and well in my book, I like to watch damn near all the boats that I see in post-modern offshore racing, but the general public gets bored.
Without "wow," there's no draw - like the first time you see a NASCAR car rip by at 200+ standing on the wall, or an indy car go screaming past you standing on the sidewalk in a grand prix, or a monster truck crush some cars, or a top fuel dragster launch with a deafening report, or a turbine-powered 200+ mph water-rocket. It's all the same, the first time you feel it, you're hooked.
I think the supercats getting together with the hydroplane guys is a fantastic idea...as is their recent push to band together and strive for a common objective and selectively decide when and where they race, not for whom.