Australia is a federation, much like the USA. It's founding fathers did not have any intention of creating a homogenous group of provinces such as exist in France or Britain. In fact, the rights of each state trump those of the Federation in most instances besides limited, enumerated, common interests as specified in the Australian Constitution which only got drafted in 1901. Such matters as national defence, maritime laws, national highway maintenance, etc.
Most people struggle to understand this. States rarely combine forces to produce anything, let alone any big events. It's probably a big reason why we failed in our bid to host the 2018 World Cup. The distances between each state's capital cities are enormous in comparison to those between counties in GB, or even the states of the USA. The sheer logistical complications to move an event literally thousands of kilometers per stage would be simply ridiculous. Look at a map of Australia and compare distances with those of England or Europe. I hope this task will allow some trolls to feel slightly less insular for a few moments.
Each state was a separate, unrelated colony when founded. Some like SA were not colonised by the UK dumping convicts. This is why SA is classy, and Victoria is feral. ;o)
Other colonies like WA strongly resisted Federation and merging with the other states as part of the Federation. It took WA a long time to agree to being a part of the federation as we now know it. With all their natural resources and vast wealth, they still whinge from time to time about not being separate from the rest.

Much like how New Zealand is still a separate "colony" and nothing to do with Australia - and nowadays obviously a separate nation-state in it's own right.
Little known and shocking trivia fact for many: to this day New Zealand's Constitution still has a clause within it which provides the option for it to merge with us as another Australian state! It frankly should be.
The Australian Constitution document protects each state, as separate entities, from having their rights and interests encroached upon by the Federal government. Where the states were stupid, the Federation intervened. Things like railroad guages were standardized nationwide, for instance.
This is much the same as per the USA. It is very different from the UK in that regard. But it differs from the USA in that it maintains a Westminster system where laws, courts, and Parliament are concerned.
Our federating fathers of 1901 borrowed heavily from the way the US was set up and gradually federated. We are a direct cross between the USA and the UK down here.
Our distances are vast and not comparable to any other federated nations on earth. It's a little known fact that each state down here has, by default, nothing to do with each other in terms of governance.
That's why SA's government funds it's own race and none of the others want to. As a tax payer in SA, I help fund the event. ACF, as a Victorian, does not. Therefore the race stays here.
SA is south and is the bottom, central section of this continent. Adelaide, being on it's southern central coast, has a point when it says it's Down and Underneath the vast majority of the rest of the continent. We're Down and Underneath most of it. We hold a bike race in our Federated, but separate, state. We call it the Tour Down Under, not the Tour of Australia.
We are sorry if you feel short changed or angry about this. We are sorry we bothered setting up a race down here. If you dislike it, you're welcome to continue pretending we don't exist. We are sorry we are not European and we are sorry we don't share your timezones and seasons. We are sorry we have set up a competent-enough event to attract UCI support. ***** more if this annoys you. It's of little consequence. We're here to stay. We're sorry. Deal with it by ignoring us and denigrating us if this makes you feel better about yourself and your snowed-in, overpopulated location. We'll continue holding an event and we'll keep doing the best we can. You're welcome to hate less, reduce your cynicism, and join us in enjoying it if you like.
Otherwise consider dealing with your displeasure in whichever way you see fit. Just troll a bit less. You don't own the sport and your trolling demonstrates that you sure as hell aren't better than anyone else. you're quite a bit worse in fact.
Thanks and hope this helps!