Probably clearing the schedule for American Dad's return. We'll be forced to suffer through the Simpsons and Family Guy for the rest of our lives, and Fox knew there would be a revolt if they tried to cancel Bobs Burgers. So the second best show was the sacrifice
Unless it's Simpsons or Family Guy, I think "long running" is misleading. Bobs Burgers just celebrated its 14th anniversary, and that's still only half as long as FG
