unfortunately this is one of those "gaming the game" things that we all have to put up with. There have been a bunch of suggestions as to how this could be stopped, but HTC hasn't implemented any of them at this time.
Is it realistic? no, but when you are playing a "game", you play the way you want, and the game allows. So for the WWII Simulation type flyer its wrong and ya just don't do it, but for the gamer type, its the quickest way to get things down.
Just shoot them down before they get there bombs off, really get them mad