The point is not being abrasive or obscene. Its being openly racist.
You'll have to provide a link or some other evidence showing Barr using racist "humor" or being similarly racially divisive.
I probably should use the word "bigot" for Roseanne, since she deals with gender and homosexuality and well as race/ethnicity, and her prejudices morph over time. In addition, she has long discussed her struggles with mental illness and can be kind of unhinged. P.S., I really like Roseanne -- she's a comic genius.
So this is the good Roseanne, from her old show that I loved: “Black people are just like us. They’re every bit as good as us, and any people who don’t think so is just a bunch of banjo-picking, cousin-dating, barefoot embarrassments to respectable white trash like us.â€
Then there's 1991: Mormons are NAZI Amish. Lesbians can't hate men because they don't have to f*** them. Actually too many man-hating jokes to count. Plus all the fag jokes, despite her gay siblings and her gay cast mates.
There's the dressing up as Hitler and baking "burned Jew cookies", talking about Israel as a NAZI state (mid-late 2000s). Then she switched it up to hate Muslims and people who were anti-Zionist and said that they should nuke everyone at UCDavis after evacuating the Jews. She has made too many "eat the rich" jokes to count. The latest this year was her dismissal of black and Asian tv sitcoms, which you might consider a stretch.
My point is that she, like Amber, likes to skewer groups of people in uncomfortable ways And her jokes are often incredibly divisive.