Also see:
Why African Americans Loathe “Uncle Tom” (NPR)
Many African-Americans don’t hate the real story that Stowe wrote. The Uncle Tom character that she gives us is extraordinarily Christian. The climax of the story really comes when Uncle Tom is asked to reveal where two slave women are hiding, who had been sexually abused by their master. And he refuses. Knowing that he is going to be beaten to death, he refused to say where they are. And African-Americans who have read the novel can appreciate what kind of heroism that took for a black man to sign away his life to save two black women.
Unfortunately, the stage depictions don’t include that part of the story. They grossly distort Uncle Tom into an older man than he is in the novel, a man whose English is poor, a man who will do quite the opposite, who will sell out any black man if it will curry the favor of a white employer, a white master, a white mistress. It’s that distorted character that is so objectionable to African-Americans.