Earlier quoted context omitted.
Welcome to international travel! Countries are sovereign entities and decide who gets through the borders. For any international gathering, there's going to be people who have a hard time making it through, or are unable. I was once invited by a company to an US based developer meeting, and couldn't make it because the company didn't realize I needed a visa, and it's absolutely impossible to get one in two weeks barr…
I think that an international sports event in a country that is too picky has no chance to stay relevant, especially if that means that it filters out some of the best athletes.
While I don't know much about Australia, I'm pretty sure a tennis tournament is not their biggest priority right now.