Well in 2014 the WCC at the SFS got 31,515 (Sydney Roosters v Wigan Warriors).I understand that it may be a more successful product over there (the fans seem to respond to it much more than they do in Australia), but I am not sure that is sufficient justification to limit it to two or three games in Australia since 2000.
Even when the English club teams used to win it most of the time, everyone knew it was because the Aussie club teams were treating it like a trial match and a lot of those English club teams would have a lot of Aussies in them anyway. We don't always have the World Cup in England to "help the game".