I know that you were portraying the very real love between a black housekeeper and her white family. But you were also portraying the everyday tragedy of human beings coping with their personal limitations and the prejudices (not just racial) of the people around them. We are prisoners of ourselves. But there is hope. And Ethel provides us hope in the end by being inspired and taking responsibility in her love for the family she has nurtured to overcome her alcoholism.
I can only guess that some people were bored, because you were presenting everyday life situations, not extraordinary ones. It is their loss.