In a word, glare. Think about how it looks indoors, when you have a lamp without a shade. Parts of the room have glare; other spaces are in dark shadows. That same bulb under a lampshade, however, will produce a more attractive, usable light, as well as create a mood for the environment. It’s a similar principle outdoors. A traditional spotlight might do a great job of lighting up the front porch, but leave the walkway in shadows or complete darkness. A sudden change from bright light to darkness also impairs visibility. With low voltage landscape lighting, fixtures are installed to provide a subtle, even light. And most people will agree, the light given off a low-voltage fixture is simply more attractive than a spotlight.