It always strikes me as odd that so many maritime civilisations in and around the Pacific and Indian oceans, yet it was Europeans who ultimately colonised Australia. Were there specific reasons as to why the Maori or the various Indonesian empires not only didn't colonise Australia, but seemed to have not even discovered it?
Update: Far more relevant answers linked in the comment below. Upvote the actual expert!
It doesn't exactly answer your question but it would be remiss of me not to point out that Australia was inhabited and filled with a significant number of people with a long history of their own. They pretty clearly discovered it quite early.
Hopefully someone will be along to tackle your question properly, but let me recommend some reading while you wait. /u/b1uepenguin discusses Polynesian and Austronesians explorers here.
/u/Djiti-djiti has written some fascinating posts on the life and history of Indigenous Australians and their settlement of the land down unda. Check out;
The history of controlled burns in Australia that stretches back 60,000 years.
A post on some bad ass Indigenous Australian women.
and finally, Did Aboriginal Australians live an anarcho-communist greeny utopian lifestyle?
Some good answers here, just one minor point: it seems fairly likely that some Polynesian seafarers did arrive in Australia before the arrival of Europeans (since then of course there has always been Polynesian immigration to Australia). In the late 13th century, very shortly after the settlement of New Zealand, a group of Polynesians sailed on and settled Norfolk Island (which today is part of Australia, even if that isn't exactly what you were thinking of). The settlement did not prove permanent, and at some point before the late 18th century it was abandoned. In the 1920s some members of the newly-formed Anthropological Society of New South Wales were at Dark Point in looking for Aboriginal artefacts during their Christmas break, when they found what they identified as an adze blade "of undoubted Polynesian origin". Further analysis of the adze in 2014 showed it to be most likely from Norfolk Island. The authors also talk a bit about why they think it's unlikely the adze arrived in recent times.
So it seems pretty likely that at least one canoe-load of Polynesian sailors, after making the 700 km journey from the barely-discovered Aotearoa, made it across the further 2,200 kms to the Australian coast (which is a lot harder to miss than reasonably tiny Norfolk Island, but also a lot further in a slow boat). Whatever the nature of the contact though, there was no certain lasting impact (the authors of the 2014 paper suggest the introduction of a particular design of Aboriginal fishhook, but the link would be hard to establish). The invasion and colonisation of inhabited islands wasn't unknown in Polynesia, so the reason for no colonisation isn't as simple as a lack of cultural interest in already inhabited places. However Norfolk Island was itself a pretty marginal climate for the tropical Polynesian crops and ways of life (the colony there didn't survive), so it probably wouldn't have been possible to adapt the lifestyle further to the Australian mainland, even if the locals had allowed it (obviously assimilation, or an attempted return voyage could have occurred and would not have left evidence).
Also, a pic of the adze before they took a slice out of it.
