Now this I can agree with. As the Grio article noted, the subject matter, slavery, wasn't presented in a "smart" way (see SkudderJames' video of the comic talking about Reverse Racism. I've NEVER seen a smarter comedic telling in my life! Bowled me over). While she told nothing but truths, the straight forwardness of them was, well, not funny (to me).The problem was the handling of the subject matter and perhaps the performance limits of who delivered it.
But it's not like she's the first.... or the only comic who just wasn't funny.