The "half a nuance" is true. That is, hunting is a form of conservation that often makes sense. The argument here however is not about hunting. It is about the trophies.
You see, traditionally the trophies include the tusks - and will again. At the same time, ivory elephant tusks are highly sought and used in illegal trade. This has lead to poaching and the near extinction of Forest Elephants and wild Asian Elephants.
If you want to allow trophies, minus the tusks, then I would agree maintenance and sport hunting is acceptable. But any opening on a legal Ivory trade fuels the illegal ivory trade and the merging of the two. And that has lead to and will again lead to catastrophe.