Many reasons but not related to safety, old or new aircrafts
Incheon is their hub. They can carry passengers from many cities via their hub to the States. That is better than they carrier passengers only rely on point to point. Therefore, they can offer that cheap ticket
OR
Promotion with limited seats
但好唔好.會唔會出事? Who can tell you?
People always say Singapore Airlines is good? It even happened to Singapore Airlines in Taipei(31 Oct 2000). SQ006 from via Taipei to Los Angeles. Take off from the wrong runway during typhoon...Who can make comment?