H1-B's will have to go home when their contracts end. But that's the premise of the program. It's not a ticket to permanent residency despite the fact that this is how it is used.
> Dual Intent: The H-1B visa type carries “dual intent” which means that the holder may intend to return to his/her home country or intend to immigrate to the United States.
However, it does fall under the broad category of temporary work visa, which is possibly why people wrongly assume it’s a “contract” visa.