The reason this is important, is it enables the customers who have paid on a credit card and are near their card limit, to shop for another flight that can get them to their destination on time, or closer to the time the customer needed when they booked the airline flight, that is NOW delayed by the Airline...
Same with people who are cash on hand limited....if they paid cash for the flight and limited on additional cash to buy an additional ticket from another airline that will get them to their destination closer to the original destination arrival time, instead of being held down to only the airline that your flight is delayed by.... this is a way to stop or move through easier, airport and airline back ups, confusion, and unnecessary delays....imo