It is a shame that the application for FIS was denied but closing down ops in LGB because of that would just be sour grapes. LGB is an outstanding facility post-renovation and an excellent west-coast hub for B6.
Honestly if B6 slows or stops servicing LGB then I will probably switch airlines. They would need massive upgrades at LAX to compete there and SNA/ONT are nonstarters given how far away they are.