I don't see any problem here: I'm just calling things by their names.
If I steal a movie before its release and watch it myself, then I am simply a thief. If I steal it and share it, then I am a pirate, and this version of the movie is a pirated one.
Modding games is not piracy if people don't charge money for it, if they don't position the project as a "killer of the original," if it is not explicitly prohibited by the license agreement.