It is not ignorance that this type of water bomber is not used in Australia at all.
They just aren't suited to Australian conditions. Not enough freshwater lakes is just the first problem. Slow turnaround times was the next killer. Basically effective aerial firefighting in Australia requires a constant knockdown type aerial attack. If you spend all your aerial firefighting budget on one aeroplane that has a twenty or thirty minute turn around time, your obviously being less effective putting the wet stuff on the red stuff than if you were spending your budget on multiple smaller aircraft which allow a constant attack on the fire with constant knockdown, which prevents flareup. Further, smaller aircraft are able to place their drops more accurately, and having a larger fleet of aircraft at your disposal it doesen't matter if one goes U/S.
Bigger isn't always better boys and girls. The experience of the NSW bushfire service with aerial firefighting is extensive, and their strategies for combating fires here are well planned. I know that all pilots like flying bigger aircraft, and that is the theme that I have been reading a lot here, but the fact is that greater numbers of smaller aircraft are more effective firefighting tools than one or two heavy aircraft. (can you guess, I have had a bit to do with it over the years??)
Regards,
PrUnIe