The inciter should have been talked to as well.
What kind of community are you promoting where the people who call out others for racism/sexism deserve to be punished? I doubt fgdsfg was banned for arguing. It seems likely it was due to either him being reported for racism/sexism or due to linking to an 8chan board associated with currently active harassment. CPS didn't engage in racism/sexism and fgdsfg did. It's as simple as that.
Why do people think cps should be banned/talked to by the moderators?
Well, too bad about Fgdsfg, it's a harsh call but understandable. I know it's more of a touchy subject over there in the US, I don't believe his actual intentions were bad or racist in nature.
He was doing the equivalent of a child holding his finger an inch from your face and shouting "I'm not touching you!" And he followed that up by getting indignant when people said his behavior wasn't acceptable.