It's an invitational tournament that actually started in 1976 as the Canada Cup. The main goal was...and still is...to showcase the best players in the world, which I think it does.
Unlike the World Championships which take place in the spring while NHL playoffs are also taking place, the opportunity for the best players in the world to play in a single tournament is actually a reality here.
The argument that more nations should be involved is a weak one based simply on the demographic of player breakdown in the NHL by country:
http://www.tsn.ca/canadians-do-not-make-up-the-majority-of-nhl-players-this-season-1.380861
Team N. America allows for the younger stars in the U.S. and Canada that are left out from representing their respective teams due to the simple roster number restriction.
As well, Team Europe includes players from Slovakia, Switzerland, Germany, Norway, Denmark, France, Slovenia and Austria.
Although the title "World Cup of Hockey" may be controversial, this format is as close to a true World Tournament as the game can present. To call it a "fake tournament" is simply an ignorant and uninformed opinion.