Grunge style is a protest to glamor style and ideal unreal beauty. This style became popular after wide distribution of the style Web 2.0. As we already know, Web 2.0 is characterized by smooth gradients, accurate shadows and unnatural glare. Grunge is an opposite of web 2.0. Dirty, unkempt, defiant... it is all about grunge. This style gives the opportunity to stand out among the bright, but uniform mass of neat sites.Different, but attractive and engaging has its appeal.
I'm hoping someone will do a post on Steam Punk style next. :-)