The tonality of a black and white image adds a special depth to the images that just can't be done with a traditional color photograph. It is even more important that the photographer control the light with black and white to create those moods.
Color has become a crutch for some photographers, so worried the perfect red they overlook the other key elements to a photography. Black and white, with the constraints it poses, forces the use of all a photographer's skills to get a great image.
Digital photographers have it even tougher. A portrait / headshot shot in black and white digitally does not have the same available range as film. Some of the typical techniques to work around this in landscapes such as HDR, do not work practically with a person whose expression and eyes are key and move just the slightest bit between frames.
There are other techniques that a skilled digital photographer can use to work around this, but it is a skill that takes time to learn.