What makes evil so seductive is that it travels in the guise of good. People will commit, overlook, or excuse horrific acts because they believe the acts do some good or act against some evil. The Devil knows this; it has been his most powerful tool to corrupt since his rebellion against God.
The actions of Hamas against the people of Israel are truly evil. The blithe justifications of the attacks as some sort of liberation or fight against a greater evil serve no point other than to perpetuate evil. True, many of the people making those justifications may believe in their heart of hearts that the actions do not serve evil. But, again, that has always been how the Father of Lies operates.