Neville_Nobody:
A PC12 and a C208 can be - and often are - both licenced to carry fare paying passengers at night or in IMC, so ME is not necessarily a requirement for fare paying passenger transport ops under IFR or in IMC.
In this particular case, the actual weather (don't know about the forecast - did not see it) may have suggested that an IFR aircraft and a pilot current and confident in IMC may have been prudent.
If this was a private flight, then a private pilot can fly non-fare paying passengers in IMC or at night is a SE aircraft - provided the aircraft is IFR rated, and the pilot is licenced and current to fly IFR.
If the pilot wasn't IFR current or confident, then IMHO it's always best not to go anywhere near IMC until the pilot gets that sorted.
"In some countries a King Air or even a Lear Jet is the cheapest aircraft you can get".
That's a double edged sword, isn't it.
Some of those countries also don't have the same level of regulatory oversight or safety requirements that Australia does, that make Aussie aviation both ludicrously expensive and (in general) mechanically safer than overseas.