They seem to be missing the Arckaringa Basin. Massive find, mineral extraction friendly company, existing infrastructure and companies. Water could be a problem, but that seems to be a common issue that is usually overcomeable.
What am I missing?
I think you are confusing oil in place with technically recoverable amounts of oil with current technology.
For example, in the Bakken Play, recovery rates run in 4~6% range. Meaning 94~96% of the oil remains in the ground after production is complete with current technology.