Forms make the Web go 'round. Without forms we wouldn't be able to log in to web-based email accounts, order books with one click, or trade stocks online. The downside to forms, however, is the generic way in which browsers display them. In short, HTML forms usually look ugly and boring.
The default rendering of online forms usually includes beveled input and textarea fields, as well as boring-looking buttons. Such a look and feel might be acceptable if you are making a form for use on a small intranet or on a personal web page, but it is unacceptable if you want to project a professional image.