This is just direct a interpretation of the law. You should be upset with Australian legislature for creating this type of laws not with courts that are tasked with interpreting it.
> The objects of the EPBC Act include providing for the protection of the environment
> The principles of “ecologically sustainable development” are given meaning by s 3A which provides:
> (c) the principle of inter-generational equity—that the present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations;