One of the main deterrents the conducting these flights will be no NVFR allowed,especially in the winter months. Once you get west of the Blue mountains few private pilots hold an IFR rating as the weather is just not bad enough on average to justify the cost. Also west of the Blue Mountains most of the flights are all day affairs, as to take someone to the city for an appointment,wait until they are ready to return then get them home again,it is usual to run out of daylight on the way home. Few pilots would bother with the hassle or be able to get enough time off work etc to overnight, not to mention the cost, so will withdraw from the service.
This doesn't take into account the stupid decision in the first place. Someone at CASA has decided NVFR is too risky. I call BS on that having flown NVFR for 30 odd years. So long as you stick to the rules such as weather minimums, lowest safe,fuel reserves for alternates etc, NVFR is quite safe. In fact IMHO what is more risky is single pilot IFR op's in clapped out equiptment in poor weather with the pressure to get the job done so to turn a profit.
Very few NVFR flight turn into disaster. The ones that do invariably are not NVFR pilots at all but day VFR pilots that get stuck after dark by pressing on.
Like to know the real stats too comparing IFR flights v genuine NVFR in night time crashes as there has been quite a few of those I could list.