First of all: in real life, you can delay the bomb explosion, it would reinsure yourself, it is especially useful for torpedo boats and bombing from very low altitudes, there is also a kind of assault detonator (this is when the bomb detonates immediately after contact with the ground, but not earlier than one second). And the second: in reality, when hit by a bomb, it did not always explode, because the fuse was activated only when the detonator came into contact with the surface, the same applies to torpedoes and missiles, they must not explode at least once, but at least break, ie could not be used.