I think it's only confusing for the countries that actually consistently use the word "soccer" because of other derivatives of "football" that significantly co-exist in said country e.g. the US and Australia with American football and Aussie Rules Football, respectively. So, another term is required for differentiation, hence the use of "soccer".
It's interesting to note that after January 1st, 2005, Australia changed the name of its governing body to
Football Federation Australia for the sport of football(soccer) in Australia. The old name used to be
Australia Soccer Association.
In addition, "of the 45 national FIFA affiliates in which English is an official or primary language, only three (Canada, Samoa and the United States) use "soccer" in their name, while the rest use football (although the Samoan Federation actually uses both). New Zealand Soccer changed its name to
Football New Zealand in May 2006."
It would be interesting to find out if countries whose official or primary language is NOT English refer to the Beautiful Game as football or soccer in their name. Yo,
Ducky, what says
Finland?
So, as far as "football" goes, major derivations include "Association football (the original), "Australian rules football", "American football", "Canadian football", "Gaelic football" and "rugby football (rugby league & rugby union).
As far as the
FIFA World Cup is concerned it is definately
"FOOTBALL" as evidenced by the governing body,
"Fédération Internationale de Football Association" (FIFA), founded in Paris in May 21st, 1904. BTW, "the
Laws of football that govern the game are not solely the responsibility of FIFA; they are maintained by a body called the
International Football Association Board (IFAB). FIFA has a 50% representation on its board (four representatives); the other four are provided by the football associations of
England, Scotland, Wales, and Northern Ireland, in recognition of the unique contribution to the creation and history of the game of the nations now comprising the
United Kingdom."
Anyhow, whether we refer to it as "football" or "soccer" doesn't really matter too much. It is STILL the
World's Beautiful Game.