Because they are unique. Same reason people like customization of any kind: iPod skins, engravings, named teacups, etc. Plus, these cars usually are really flaring, no one can be indifferent.
Everyone has different tastes in cars and what they like them to look like. A lot of people like their cars to be pimped out because they like the look and the style the car brings. For some it just isn't worth the price. Pimping out your car can also add value to it.
This depends from person to person. Every one likes whatever they want to and i guess they have a good reason for it. Some like customized cars and they think they can do better than the manufacturer and some are like you who believe you cant improve the thing you have.
