Why did they worshiped Hermes?

Hermes is the messenger of the gods. He was worshiped because he protects and takes care of all the travelers, miscreants, harlots, old crones, thieves, and merchants that pray to him. If you are wondering why he protects thieves it's because he is very much like a thief himself. When Hermes was born he slipped away from Maia (his mother) and stole his older brother Apollo's cattle.