http://www.deadline.com/2014/07/24-live-another-day-season-finale-howard-gordon-spoiler/

As exec producer Howard Gordon explains, "This has always been a show that is really about the days and the life of this man and no day is probably as intense as a person’s last day. So killing Jack was something that was intriguing to us all but it had to be done just right. And that didn’t present itself to us.” PLUS: How producers arrived at that ending (http://www.thedailybeast.com/articles/2014/07/14/24-live-another-day-showrunners-on-the-finale-the-dangers-of-drones-and-jack-bauer-s-future.html), Tzi Ma says: "You couldn't ask for anything better,” (http://www.tvguide.com/News/24-Live-Another-Day-Postmortem-1084326.aspx) “Live Another Day” was a terrific season of TV (http://www.avclub.com/tvclub/24-live-another-day-1000-pm1100-pm-206901), Kiefer Sutherland deserves credit for the powerful finale (http://time.com/2982802/review-in-24-live-another-days-finale-jack-bauer-feels-our-pain-again), and this season played like “Jack Bauer’s Greatest Hits." (http://www.hitfix.com/whats-alan-watching/season-finale-review-24-live-another-day-10-pm-11-am-bye-bye-jack-bauer)
Read more at http://www.hitfix.com/tv-tattle#KgGmP43efq2u4oqB.99

Killing off Jack would mean death to a great show and a great character.