Saying that racism is bad is subjective. However, that doesn't mean that we don't condemn racism.
That's assuming you're amongst people who are racially diverse or don't care about race.
If you were at a Klan meeting and people were throwing around racist jokes, they might all find it hysterical whereas if you go to a Diversity Club they'd find it sick.
Point is: With a joke everything is subjective. What is right to one group is wrong to another and vice versa.