Yeah, I think the point Chappelle was trying to make was more "why is it okay for me to use this highly charged racial slur every single night on your network, but I'm in your office because use this other one once". It's not even clear whether Dave was the one using the word "fa**ot". If it's a quetsion of network standards, why isn't he being told he can't say ni**er either?
I see the argument you're making, but again, in keeping with the theme of the article, it's a question of why we're so selective about the things we consider offensive. That applies to things like the n-word too. I've actually written about that subject.