I know this is a HUGE issue in the replica prop world.
If I personally sculpt a movie prop helmet and cast from that sculpt and then sell the cast to others......how can I be upset if others cast off that sold item.
I have no rights to the original prop, regardless of how much I paid...........all I did was copy.......and others copy it....
I think it all comes down to people pissed off because THEY think on some level the prop they sculpted or rendered it on some level.
There is no OWNERSHIP.............The right to copy is held by the people who BUY the license to copy.
Mostly at the RPF......all we do is fan based COPY.