Well, I would never leave an aircraft at the end of duty until the rest of the crew were all done, the sole exception being if I have another flight to operate that is in danger of delay if I dawdle, in which case I bid my farewells and hit the ground running.
These days though, a more common scenario is to walk out of the flight deck saying 'Everyone ready? Lets go', to see an empty cabin (divider gently flapping in the breeze, equivalent to a piece of tumbleweed blowing through a ghost town) because the cabin crew legged it 5 milliseconds after the final passenger.
CPB