If you look back at what I said, I did not say that it's acceptable to make fun of white people cause they are oppressors, I said it's more acceptable because they aren't oppressed.
You are correct when you say "context is everything". Which is what I have been talking about, the context of making fun of white people and making fun of black people is different. And yes, the context of which group or what stage you make the jokes on matters as well. If you want to make these jokes with your friends, of whom you are sure they consent and are fine with it, by all means, if that's what you enjoy, but once you extend it to the greater public, for example by making these jokes loudly in public or posting them on a forum, that is a context that to me changes the dynamic.
So again, a racist, sexist joke, the punchline of which seems to be "haha rape is funny, haha, black people raping white women, that's something people think, that's funny" ... I don't see the value in that, in fact, I see the harm that these attitudes have brought to society, and that's why I suggest people don't do it, and think worse of them if they do (again, you may note that nowhere do I forbid anything, I don't have the authority to do so even if I wanted to).
And I think the right to say what you want goes both ways, if you want to make a racist joke no one is stopping you, if people then want to point out it's racist and shun you for it, that's fine too.