The Range and Target values are the standard values for non-attached Conjurations. The way the card works, as you have pointed out, didn't require an exception to those standards.
I think the only reasons it might require an exception is if there ever is a "zone bind" trait (like mage bind) or a spell that can counter spells that target a zone, or if someone wanted to attack and damage an indestructible object. I wish that were allowed, I can't imagine why it's not, if it already can't be destroyed, then what's the point of preventing all damage to it too? If there were ever a way to remove the indestructible trait of an object, then would it just have 0 life and die instantly? What about objects that gain the indestructible trait?
If it targeted the whole arena, then it would always be in LoS. It would be cool if there were objects that targeted the whole arena. They could be attacked and targeted by spells and effects from anywhere, but they'd also be able to affect the entire arena.
