Dave Chappelle is a comedian, they say stuff like that all the time, it's part of their job. If you are going to quote somebody (specially on these issues), I'd recommend not to quote a comedian.
Michael Richards is a comedian, and made anti-Semitic remarks that resulted in a significant backlash. Again, looking back this is a good indication of someone saying something that was NOT popularly acceptable.
Removing the context from that and hitting Chapelle for it is just a convenient target.
Chappelle was commenting on a widely held belief. Richards, not so much.
Edited the above to make that clearer.
That's what comedians do. Listen to Louis C.K (or anyone, really).
>Michael Richards is a comedian, and made anti-Semitic remarks that resulted in a significant backlash
Depends if he made them as part of a comedic routine or not. And actually even when part of a routine, depends if they were told as genuine preaching / ranting, or just for the comedic effect / exaggeration / black humor of it.