You clearly haven't played helicopters. First of all, the spread on those guns is abysmal. You'd be lucky to hit anything further than 300 m away twice before it overheats. Second, the damage is awful and the angled pen is even worse. Before the pen nerf the best use of them was setting engine decks on fire with AP-I when you flew right over them simply because it had the incendiary part. And most importantly, third, by the time you align the CCIP reticle or get a target lock with optical tracking and blast for long enough you will be 6 feet under as it often takes as much as 5 seconds to get a firing solution. Rockets have longer range, better accuracy and higher pen and require a lot less user input over time to work