As a watercolor student of Irving Shapiro, I was told never to use black in my paintings. I was never given a reason for not using it. But I followed his rule, and to this day, I do not use black in any of my paintings.
Also, in my painting classes I instruct my students to never use black in their paintings. No matter the black that you use–whether lampblack or ivory black or boneblack–the tendency is to use it anytime that you want to make a color darker in value.
You have a much greater variety of color choices when you use other colors to make a color darker.
However, Faber Berrin in his book on color, "The Principles of Light and Color" states that color harmony is achieved by tints -a hue or color with white added, and tone–a hue with black and white added, and shade–a hue with black added, as shown in the chart below.
Some of my favorite artist of the past used black in their paintings with beautiful results.
John Singer Sargent
Though I have never used black paint in any of my paintings, and will still encourage my students to avoid black initially, the creative process is a continual journey. So adding black to my palette will be my next great experiment in painting. Stay tuned!