Melbourne is a great tech hub, but nothing compared to SF, SEA Aand NY. There is no real way to get funding from public investors, you have to talk to "old money" (though this was a couple of years ago, this may have changed).
There was a great article I read a while back talking about Atlassian's move from AUS to USA.
When they were starting up JIRA they had to do it from $10k credit card debt. No investors in Australia wanted to touch them. So they moved to the USA and got funding almost immediately.
From memory Atlassian was profitable very early on. I'm not sure what's wrong with investors there. A lot of our economy is run from raw materials, so maybe they just don't get it?
EDIT:
My experience is that software engineers are very intelligent there. I've worked with a lot of smart people in the gaming industry and mobile.
The issue is a lack of leadership and funding.