Simon,

That's crazy and would never work (except for on a very small level). Seeing a black and white photo of a cat flying a hull in the local paper is going to do nothing to draw people into the sport, not much anyway. What you suggest would require a unified, organized, and sustained effort by all clubs etc. at the same time, and I don't think that can happen.

I don't think Hobie Alter had the mentality of only converting existing monosailors to catamaran sailing as a way to advance his business.
I think the reason all catamarans are thought of as "Hobie Cats" to the general public is because their appeal reached way beyond the sailing community. And that's what needs to be done to make them "pop" again. And to do that you've got to make them look good.