No room in your house is complete without having the right switches. No matter what type of room you are making for your house, having the right panel to match the wall and the theme of the room is absolutely vital. Once you own your own home, you want to make it yours - and having the same white panels for your wall plates that everyone else has is not only boring, it's unoriginal. Only people in college settle for how the house or apartment came initially - everyone else paints their home to match their personality and style.
If you have a guest room, don't you want it to be inviting? Many people paint their guest rooms in muted colors, with soft light and decorations. Having a set of plain, white, switches can be incredibly jarring in an otherwise uniformly relaxing atmosphere. Your guests are supposed to be able to feel comfortable, and yet having something sticking out of the visual integrity of the room can be quite jarring and give the room an unfinished or sloppy feel.
Consider also that having the right set of switches can really make the room theme pop; such as in the case of a 'man cave'. Almost every guy wants to have an office of some nature, and usually these places are dark and somber, filled with heavy and imposing furniture. Consider the benefit of being able to have the dark and muted tones that make for a good sports den and man cave, as well as having the dark tones for the wall plates so that they do not stand out as bright white spots amid the dark paint and deep colors.
Finally, there are a number of switches that can go in other places in your home. For example, you can install a dimmer in your dining room to be able to control the light level between homework and project night or a romantic dinner. You can even get multiple wall plate options where you can have the controls to many electronics routed through one panel, such as in the back yard where you might need to control various lights as well as pool controls.