As long as lighting designers have competed for awards, fill light has been a hot topic. In the hands of a master photographer, fill light makes every part of the interior visible. Not only is this preferred by design magazines, it often makes the lighting look better.
However, from a lighting designer's perspective, fill light is cheating. It adds sources not specified by the designer, often to compensate for shortcomings in the lighting scheme. Fill light is as dishonest as, well, digital-image 'surgery.'
Should you add fill light? That depends on your needs and skill. I suggest a small amount of light, such as a table lamp beneath the tripod or an umbrella lamp near the camera, to eliminate foreground darkness. Having been a lighting awards judge, I believe this is minor and should not be held against the photographer or designer. But big-time fill light, such as massive uplighting of historic buildings, is another issue. It's not honest to show glorious architectural details that were only visible during the photo shoot.