thatPolarBear
1. To look cool.
2. To just have 1 ship to warp in BH mode.
3. To be able to easily repair and produce more fighters.
4. To bamboozled people in MP who set a 1 ship cap.
5. It makes for interesting designs.
6. It's fun.
7. It looks cool.
Most of these don't even involve AI but I think you see my point. There's something incredibly satisfying about dispatching a bunch of fighters from a main vessel. You're right that it's not completely necessary to the game but we already have explosive charges as a block so why not give them more utility.
Edit: just wanted to say I think the explosive charges work fine when directly piloting a craft. But I use the battle helper a lot and I don't like it when I have to intervien in a battle to use a carrier ship correctly. Also it could make for more diverse ships in BH mode which would be welcome.