This video explains some of the frustration I've had with arbitrary sound choices.
For me the question first arose when numerous friends shared this video with me:
I understand the tree rings are triggering the piano but it seemed like sleight of hand when they suggested I was hearing the tree.
Then there are the contact mic apps that use the sound source to trigger a sample. Again it's a somewhat arbitrary process to suggest the object being struck is creating the musical result.
I think sonification is an interesting process but one that would be better described as a musical metaphor.