Algeria was in a state of civil war at the time of the hijacking. Aircraft flying to Algiers faced the possibility of missile attacks. As a result, Air France's flights to Algiers had crews entirely made of people who volunteered for the route. Air France had asked government officials if it absolutely had to continue flying to Algeria; as of the time of the hijacking, but they never gave Air France a reply. Bernard Delhemme was the captain of the flight. Jean-Paul Borderie was the copilot, and Alain Bossuat was the flight engineer. The Airbus A300B2-1C, tail number F-GBEC, had first flown on 28 February 1980.
Please see the question in the title.
Why would rational air crew volunteer to fly to a state with civil war, like Algeria? Did they have optimism bias? How did they underestimate the risk?