It is an unwritten rule that you try to be as civil as possible during war because that enemy that you are killing may eventually surrender and you can have peace. The losers will accept your demands and you can go back to your fields and factories and carry on with life.
The problem with Hamas and in general Islam, is that they do not want peace. Never! Their religion tells them that if they die a martyrs death, they will be rewarded in heaven. You cannot negotiate with that. Never!
With that kind of attitude, you can never have peace so the alternative is that you kill as many as possible. A dead martyr is no longer a threat.
This is a sad fact that people, in the civilized world, do not realize. They don't realize it until they are confronted with the threat themselves.
All I can say is that I am not the one who has to make the ultimate decision. We all sit back in our arm chairs and give our opinions. The person who gives the orders or is ordered and carries out those orders is the hero. But we all live from the consequences and have ownership in these ultimate decisions.
Humans and humanity suck! There is no way around it. Well there is a way to forgiveness and it is our only hope.
The idea is to make it easy for your enemy to surrender. If they know their fate is most likely death if taken prisoner, that only stiffens their will to fight. The Nazis found that out the hard way in Russia. If they treated the Ukrainians and Russians better, the Red Army would have capitulated.