Remoak
My point was - its not so easy to get your situational awareness of where the other traffic is when transmissions from the other a/c are being continually crossed,jammed or where the language barrier makes it difficult to understand.
I also note flying around a lot that in a number of CFZ's around the country the regular users seem to use a lot of 'local' points not displayed on charts. This is also particularly annoying as you have to trade off looking out the window to looking at your chart to try and find the reported position on the map, only to find its not on there. It's one thing for you to be on the ground and wait patiently for a break in the RT or sit there while you work out where everyone is, as you say, but its not so easy when your already in the air given the above circumstances.
Yes you are correct - FI has a discreet freq 124.1 but I was generalizing NZ wide not specifically to this accident. Years ago when everything outside controlled airspace was 119.1 was just a shambles. As a jump pilot - at altitude you would pick up half of NZ - it was a bloody nightmare where you would have to endure squealing and screeching from multiple transmissions at once for the majority of every flight.
Anyway, I understand what you are saying and it would be great in the perfect world, but I can't see it being the be all and end all of preventing this sort of thing from happening again sadly.