I had this same discussions with a group of New Zealand'ers a few weeks ago on reddit. I was so surprised that the vocal commenters thought it best to return all artifacts to their rightful owners. I tried to point out that one person's rightful owner is another's despot, and what about all the examples of things being destroyed at the hands of poor stewardship? The main retort was "New Zealand is not some backwater country" which of course I agree but where do you draw the line? That's when I backed away slowly realizing the frothing mob was not interested in preserving shared history as much as revenge/retribution for colonial slights.