I've already touched on that. Manasseh practiced a form of Canaanite worship (which included child sacrifice).
So it was about spirituality after all...
Perhaps to you worship of one god is no different from worship to another. But according to scriptures it does in fact matter.
Ancient Babylon clearly did not worship the God that Judah was supposed to worship faithfully either...and God destroyed it too. It is this spiritual opposition to God that prompts all this destruction.
So the scriptures most certainly place huge emphasis on this pharmakeia.