John, we'll have to agree to disagree on whether boats are relevant; as someone who has sailed most types of boats and boards I still stand by my comment.
I didn't say Moths were "so good" or that they were very popular. However, they show that you can get very good performance (often faster than boards) using just one sail across a very wide wind range, which may show that modern windsurfing sails do not have particularly wide ranges as is so often claimed.
We'll have to disagree on whether windsurfing is simple once you have "mastered the art", since I think I've only seen about three or four people who did that, and that had sail numbers like US 1111 and E11 and their sailing was pretty damn complicated.

In many ways I find windsurfing to be more complicated than my other sports of bike racing and boat sailing. That's not a bad thing in many ways but there has been a huge amount of research about why people do sports these days, and most of them find complication a turn-off, which may be reducing economies of scale for Cobra.
The GPSTC is doing well in many areas, which is great - but isn't it actually a successful example of the sport moving to a simpler model (compared to the 'old-style' equivalents of slalom racing or speed challenges down set courses) which one of the basic points I'm trying to make? GPS made speedsailing simpler, now speedsailing is bigger - so why not look for other things to simplify?
Whether windsurfing is bigger than it was 7 years ago is hard to check. I don't think it's the case in NSW; out of the series you mentioned, the only one I've done is now significantly smaller than it was 7 years ago but there are always many causes for such things. The last two times I was near my old windsurfing haunt (Palm Beach NSW) in perfect conditions, there was not a single windsurfer out - there was barely a single shortboard across all of Pittwater in howling breezes. Where I live now, the sport has apparently dropped sharply over the last few years.
I wasn't advocating a command economy, but surely it's reasonable to point out that the free market has NOT stopped windsurfing in Australia dropping to about 5% of its former popularity, and to discuss issues related to the cost of the sport and its economic basis in a thread like this. I love windsurfing in almost all its facets and have done for many years, but it's baffling why it, alone of all sports, seems reluctant to deeply consider why it may not be attracting many people. And the thoughts I'm raising are similar to those now held by guys like Sven Rasmussen, so it's not as if they are unthinkable.
JSR, neither would I, but the 50 knot figure came from Quantum Sails' TP52 information, and the previous generation certainly would have sailed in such conditions.