Point taken. It isn't the cleanest option but if Kina's need to be removed from PNG in a hurry, that's the way to do it.
On a side note, several of my former colleagues had payments as you mentioned. They just gave the PNG mastercard to the missus & she withdrew the maximum allowable on pay day (and subsuquent days after if pay was over the limit for withdrawal). The guys up there lived off a load & go card from Aus Post or a debit card from their Aussie bank.
As you rightly point out there are many ways of working around the problem, and if the benefits of working there outweighed the extra effort and inconvenience involved in these work arounds, you might tolerate it.
But the way things are working for ANG these days, (and please take my point that things are no longer anything like they were ten years ago), these inconvenient workarounds just make the whole exercise untenable.