Heads up, dudes - feminist geeks call you out on this shit for one very simple reason: not funny. Rape is not funny. Racism is not funny. Slavery is not funny. It is not funny, for several well-fucking-recognised psychological reasons to joke about things which cause actual harm to actual people, even if your platform is not real. Because one of those things that we've found out about the intersection of a culture of violence and humour is that it has very real consequences.
If your answer to this is '...but, that's not what people mean when...', then go learn some shit about psychological conditioning.