From the aluminum producers spec sheet regarding 2014:

"Corrosion resistance is only fair"

Given that the hub is an exposed, all weather outdoor use, interfacing with a ferrous metal spoke the material selection was clearly inappropriate and was in fact acknowledged as an issue by Soul.

Bottom line:

They didn't do their homework and picked the wrong material. Whether they choose to accept and correct this mistake in full or refuse to replace an poorly designed product once it is out of warranty is their decision.

But the OP isn't at fault for not washing his bike (a truly ignorant comment given that water can act as corrosion accelerant) or purchasing a used product. His expectations of Soul might be too high, but just because YOUR hub didn't fail, does not, in some voodoo spell way, mean that his didn't.