To the OP, I'm sure Toyota has extensive research to support the design of the Aussie Hilux. And they know that Australians are smart enough to not have a vendetta against diesel vehicles.
We get the "macho" Tacoma because Americans are "macho" and the majority of Tacoma buyers (few of which are represented on TW) probably still associate "diesel" with that dump truck you followed home that left you in a cloud of black soot.
Unfortunately, the discussion continues on diesel. The thing that no one seems to realize is that even if every single TW, Toyotanation, TTORA, FJCruiserForums, YOTATECH, etc. member signed a contract saying they'd purchase a diesel Tacoma as soon as Toyota made one - it still would not be enough to make it worthwhile for the company. And they obviously believe, the majority of their audience do not have an interest in diesel for this size vehicle.
The design is what I wonder about. Who does the research and decides the "sloped" front is what Aussies want? I am not making a judgement call on Aussies "tastes", more about Toyota's research into those tastes.
The America's Taco look's more "muscular" meh....That's opinion. It's simply amazing to me the research and marketing teams are able to look at a population of buyers in countries and decide what they will like and build the same truck in two very different wrappers for different cultures.