the exchange rate of Euro > NZD (1 EUR = 1.70 NZD or thereabouts) might be more likely to have something to do with it, rather than Australian aviation regulations.
Midnight,
With all due respect, absolute rubbish.
Some little time ago, I was institutionally involved with assisting one US and one Canadian group that organised flying safaris in Australia, and their trials and tribulations with the almost impenetrable Australian burgeoning bureaucratic maze.
The first killer was the ever extending time cost and complexity of getting a license validated to fly in Australia, (made much worse by Part 61) compounded by the cost, time delays and uncertainties of (ever) getting an AVID/ASIC clearance.
At all stages, the CASA "attitude" was uncooperative, varying from "constrictive (obstructive??) inertia" to a positively hostile attitude to the idea of "foreign PPLs" flying in Australian airspace --- the implicit objection was so clearly was that these "foreign" pilots would not be up the very high standards required to fly in Australian air.
There was a very obvious particular bias against FAA licensed pilots --- apparently it was/is "too easy" to get a license in US.
At one stage, there was one Queensland operator had something like fourteen aircraft dedicated to flying safaris. That is long gone.
Tootle pip!!