Of course, the principled thing would be to pull out of the AUS market, but even Apple has not proved themselves to be that principled.
I think it's actually quite reasonable and doable for companies to boycott Australia over this, and I hope we see some. It'd be free press for the company and cost relatively little - I'd imagine the press would pay for any missed Australian sales. And it'd put some pressure on the Australian government for this idiocy.
But that's not really the problem here -- it's more that Australian products and employees may be tainted by unknown government interference.
Other companies have done similar things in the past, though probably not for the same reasons.
I had a GRiD Compass laptop that had a big sticker on the back with a surprisingly long list of countries where it was illegal to bring the computer. The only one I remember offhand was Israel.
There are plenty of businesses and invividuals in Australia that this law adversely affects. What are they suppose to do?