Epic salvation is not a selfless act of righteousness; essentially, it is a transaction. The Epic, by its great power, halts the world's tendency towards destruction, preventing it from plummeting to the Lower Plane. In exchange, the Epic obtains Source Power from the world's origin as compensation.
Even in a world devoid of Source Power and life, one can't say that no Epic will come to its rescue. Maybe a creator, who no longer needs external Source Power and can open a primordial world in the Void by its own strength, might pass by and happen to feel pity and save it.
But in the vast majority of cases, Epics won't expend their strength on such unprofitable endeavors.
Different races, the creatures of the secular world compared to Epics, are so vastly tiered apart that even the metaphor of cloud and mud falls short. How much sympathy and compassion can there be?
