Population means nothing when gaming is involved, how much of Europe do you think plays Minecraft? A much smaller percentage than the USA, that's for sure. A larger percent of Australians play Minecraft than Americans, and and a larger percent of Americans play Minecraft than Europe. It's been in Europe and the US numerous times, so maybe Australia deserves a Minecon. Think about this - Australia is also easily accessible from New Zealand, from which you'll find a good chunk of Minecrafters, along with the surprisingly high amount of Indonesian and Pacific Islander Minecrafters, and we are, of course, within easy reach of the majority of Asia. The US is basically in reach of Canada and South America, South America having an abysmal amount of Minecrafters. You're oceans from anywhere.
Although, to go from Voxel MC's original post, Australia actually comes under "Oceanic"