I am one of those people who thinks killshooter is an obscenity. But, this isn't about my personal rant.
As far as programming a game is concerned there is no reason at all for killshooter to exist, except possibly one, but untill I hear an official documented response for the HiTech crew that states that one reason I will stand on the position that it does not need to be there. Here is why.
When you attack targets on the ground you know you cant damage friendly buildings right? Also, you know you can't damage maprooms. (Oh you can screw up when making an arena and set a maproom to be damageable but it's a bad thing, so part of testing a new arena is to make sure all the maprooms are invulnerable). The point of this is that the these buildings and what not are no more and no less than mere 3D objects in a 3D environment. Your airplanes and nothing more or less than that too. If those items can be made to be selectively damagable depending on whether friendlies are shooting at them or not then so can your airplanes. The code already exists within the game to do it. HiTech can patch the game so that friendly can't kill friendly any time he wants to spend the programmin hours to get it done. Other games far far older and supposedly far less sophisticated than Aces High had setups where you could not frag a friendly and there was never a complaint. It's not like it's hard, it's not like the code doesn't even exist yet. It's just a matter of useing what they already have.
Killshooter is NOT a necessity. It may be the only way HiTech & Co. can figure out how to do certain things they want to do. But, it is certainly NOT the only way to do those things. It's computer programming for heavens sake. If you can imagine it, some programmer, SOMEWHERE, can probably write code for it.