Why do people act like racism is inherently worse than any other kind of discrimination or prejudice?

I don't think it is. Look at how successful mainstream comedians are (Richard Pryor, Dave Chapelle, Carlos Mencia, Daniel Tosh, etc. etc.), where racist material is their normal routine on stage. It can be a laughing matter, when not taken seriously, or *not* a laughing matter, when taken seriously. The view on it is on an individual basis. Comedians are often racist on stage, and the crowd and TV audience laugh. If we can all laugh together at it, no one would get so offended. Laugh with people, not at people.