Officials believe Hamas specifically chose the school because, as marked on the giant Loony Toons map titled TERRORISM PLANS, there are the most kids to eat there.
map of a neighbourhood with the huge-ass school circled in red "THIS SCHOOL - NOT THE OTHER ONE" and in the margins "REMEMBER TO KILL AS MANY PEOPLE AS POSSIBLE" because I can be trusted with a gun but not with retaining basic information.
Fumbling to open the top secret laminated document while in a firefight with the IOF "WAIT GUYS I HAVE TO CHECK IF WE'RE SUPPOSED TO KILL THEM OR NOT GUYS WAIT WAIT TIME OUT TIME OUT"
If you open the map in the middle of combat, it pauses everything. Maybe Hamas is just full of gamers and had a misconception about how real life works?