They're not a child in this analogy because they lack the knowledge of right and wrong, but because they lack power.
To relitigate this analogy, it is morally wrong for the child to kick you in the shin, but it's far more useful to worry about the actions the adults are taking because, again, they have most of the power.
Hamas had more than enough power on October 7 to murder and kidnap a whole lot of people. They also have the funding and power to build a network of tunnels under Gaza which has so far thwarted the IDF's capacity to find the kidnapped civilians and bring them home.
They're not all-powerful. But thats cold comfort to everyone who lost loved ones in the attack. They sure kicked Israel in the teeth.
To relitigate this analogy, it is morally wrong for the child to kick you in the shin, but it's far more useful to worry about the actions the adults are taking because, again, they have most of the power.