a more apt analogy would be if somebody shooted in the air in the general direction of your house, knowing that with overwhelming probability he was unlikely to hit you, and in retaliation you dropped a napalm bomb in his neighborhood, killing everybody but him.

The "overwhelming probability" of being "unlikely to hit" is a bad analogy to the real world. Hamas's rockets don't kill many people, but they're not so unlikely to hit that they don't kill some people. It's not as if they're blowing a puff of cigarette smoke towards you and increasing the probability by 0.001 that you may someday get cancer--people actually die from those rockets.

Furthermore, you left out the part where the guy deliberately shot at you from a crowded neighborhood so that the only way to defend yourself is to endanger the people around him.