Reason why they die is because a lot of people import jap shitboxes. These cars have been thrashed by the japs, worth nothing, and are sold to aussies for top dollar. They are then thrashed over here, then the engines die.
It takes a fair bit to kill an rb26. The reason why they die is poor tuning, or just wear and tear. If well taken care of, they should last past 300,000 kms. Most of those 32 gtr's would have close to that if not more