It has been done to get a more realistic fusing.
This has been done with the possible features in the game.
Since there is no such thing like a seperate fuse within the bomb IN GAME it has to be determined with the bomb object interacting with other in game objects (instead of a fuse object which simply isn´t there).
Despite the correctness when compared to real bombs it is an improvement.
You never mind really dying when being shot down. This feature also is a lack of realism, like the not real complex fusing of the bombs in game.
There always will be constraints in implementing features when one considers
- game engine features
- amount of work
- schedule
And there is IMHO no necessity to make this an option. If you cannot cope with the feature, take an hour or two and practise how it´s done.
This is not a game for Johnny Joystick, you won´t succeed in Dogfight without practise, why should you succeed in bombing then?
just my 2ct!