No, you do better! Your silly appeal to emotion doesn't fly with me, sorry.
You are very well aware that Tarantino movies don't vilify their own audiences.
You are conflating two very different contexts in order to make your shoddy argument. A slave owner in a Tarantino movie using derogatory and discriminatory vocabulary makes sense, because he is a nasty racist. The use of the word is intended to make audiences despise these characters. A black character saying it to another black character would also be in line with their character, as evidenced by current real life vernacular and rap music.
In either case, I very much doubt that Tarantino movies are fostering resentment against black people, on the contrary. Movies like Django are putting racists into the vile light that they deserve and make audiences sympathize with the plight of slaves in America. That is the reason why you have no issues with these movies... myself included! A villain or nasty character hating white people and using derogatory terms, I'd have no issue with, as I also have no issue with the Riddler despite the heavy allusions.
The Catwoman line is very different from that. Yes, she is supposed to be a flawed character, but in no way are audiences supposed to regard her as a vile racist. On the contrary, we are supposed to feel for her and be empathetic to her struggles. I somehow very much doubt that DC and Warner have the intention of turning one of her superhero characters into a racist. Flawed or not, we are not supposed to despise Selina. The line was put in there not to portray her as a casual racist, but to appeal to a certain target audience who is resenting white people. In other words, racists!
If a non-black character that I'm supposed to feel sympathetic towards would be using the n-word in a discriminatory fashion, I would be complaining in the exact same manner! Imagine one of the Suicide Squad members casually dropping the line "black people are stupid", you would not be appreciative of that. And you'd be right! Movies, especially not dumb popcorn movies, should be fostering resentment towards demographics!
You'd think suffering through "decades" of this ignominy would make you more aware of these issues. You simply don't care because it is either not targeted at you, or you just want to enjoy these popcorn movies in a braindead manner.
Oh and Catwoman saying that line to the Batman doesn't really matter. First she is perfectly aware of him being a white dude, irrespective of his true identity. Second, the Batman just passively accepting her casual racism and also falling in love with her, can only mean that he either agrees with her, that he simply doesn't care, or that he's too stupid to realize it. None of the options put him in a very favorable light, but I'm somehow supposed to like that character?
Finally there is also the issue of considering Batman a "privileged character". Yes, he is rich, but he also witnessed the death of both his parents at a very young age, suffers from crippling depression, is unable to form human bonds, cannot maintain a healthy relationship with a woman, is unhealthily reclusive, has a battered and bruised body that cannot keep up with his crime fighting demands and he doesn't care about his material wealth beyond using it as a means to facilitate his vigilantism. You think it is a privilege being Batman? Think again! But you don't care, do you? For you he is simply "white and rich", that's enough.
In case you haven't noticed, that is exactly the same kind of rhetoric that the Riddler uses against Batman. He absolutely despises Batman for being a rich orphan, while Riddler himself was turned into a poor orphan whose cruel fate didn't receive any kind of attention. The Riddler is evil because he can only think in strict categories. He is by the true definition of the dictionary, a classicist with a deep grudge towards those who had it easier in life than him. That is the reason why he feels vindicated through his acts violence, because from his perspective he is merely punching up.
If you think a little bit more about that line, it flies directly into the face of everything that the movie wants to convey. It perpetuates Riddler's f*cked up worldview without even realizing it... and that, my friend, is the true irony behind it.