And "luke I am your father" and "Leia's my sister" work for me because they don't blatantly contradict anything I saw or heard in Star Wars A new Hope... not because I'm pulling this illogically out of my ass. I'm thinking of how it fits in the story, and that's it regardless of what may have been the true intentions of the filmmakers. A lot of films have no set story in place before they're filmed. This happens all the time, so I'm not surprised in the least that that may have happened here too.
and i don't understand how you say you weren't discussing them in terms of the story when you typed these words "It's not only cheap - it serves absolutely no purpose in the story. "