Monsters are often just misunderstood, and not really bad. This is all just a big misunderstanding, and a case of being at the wrong place at the wrong time. The helicopter blew up the town and the monster was just walking by. It it is not a monsters natural instinct to walk into a city and just start destroying things. Just like it is not our natural instinct to want to shoot missiles at monsters. I hope you have a wonderful day and don’t find yourself in any monster sized misunderstandings.