Why? It was in Hungary...which is very inland Europe and hard to get to from anywhere outside of Europe. There are several Austrailian teams present - the usual rock stars...but there are several Aussy teams that are usually at the worlds that aren't there too. Logistically, it is just a difficult place to get to for anyone outside of Europe not to mention that the event is being held on an inland lake where the weather conditions are less consistent than would be at a coastal venue.

Roughly scanning the countries, it appears 95% of the teams are from Europe and that only 7 are from outside of Europe. 15 are from Hungary itself. I wouldn't say that no US or Canada, or Mexico (Brazil, etc.) participation is that surprising.