I think there are some fair expressions in this thread but the problem seems to be that we are expecting this should have one answer. Well it has dominant answers and less dominant answers.
1. First ever cold water large-scale competition. Some people and teams were obviously against this from the beginning and some probably changed their mind as time went on. Should this have been considered from the beginning? Yes, but I do not think that should necessarily have dictated whether the competition would be held or not in this location. Why? Because at some point it would only be fair to start the alternating of world competition between hot, warm, and cold locations. This was the first time, so there was much speculation and negativity that affected the results. However, after hearing results from competitors with their experiences and appreciation for the diving environment, I think a lot of those prejudices will fall. I was there first hand asking many competitors about their feelings towards diving in our colder (19-21C surface) and beautiful waters, and the results were all positive other than the odd, "But it is cold!
". This event I believe has set the stage for the inclusion of cold water events in the future, without the hesitancy experienced during this one. That is a big step, I say. The future success of cold water world events will have been made possible by the successful aspects of this competition.
2. Expensive travel for everyone. Let's face it, Canada is expensive for everybody, except the americans, to arrive at. Although I agree that other places are expensive once you are there and some were expensive for certain countries, that does not change the fact that expense comes into the minds of those who are competing. If there are other factors bugging their minds, then expense can become the deciding factor. Hawaii, as mentioned, did not have any of the negativity felt towards diving conditions, plus people think of it as a wonderful holiday destination. Canada is much more specific in who it attracts for the same experience.
3. Statistics can not be drawn from a single event irregularity to predict the future of similar events. Independant of all other factors, this could have also been a year with a slight slump, no matter where it was to be held. We had the BIOS competition immediately before worlds. That is a big decision for many. Participate at one or the other. One is close to home and independant, the other far, cold, and team. A lot of people chose one or the other, not both. There is always going to be fluxuations in attendance, even if it is held in the same place, under the same circumstances.
Conclusion:
To me it looks pretty obvious why attendance was lower than expected. I do not believe this means the competition was not successful. I think it has done a wonderful thing for the mindset towards this sport. If you are going to compare people's abilities, compare them on equal grounds. Cold people have to go to warm waters, warm people have to go to cold waters.