BUR is actually Burbank-Glendale-Pasadena airport, and is managed by a board made up of officials from the three cities.
Local citizens, especially those who live in Burbank directly in the airport's flight paths, are strongly critical of increasing air traffic. There are even special rules for takeoff, so that planes minimize noise. In other words, it's a tough challenge for airlines to increase service out of BUR.
BUR-JFK? probably not . . .