Much is made of Hamas supposed intentions to destroy Israel. Even if true (and whether this intention exists is controversial), it's completely irrelevant.
What is relevant is that the residents of Gaza, human beings every one, are being denied ordinary civil rights by Israel and Egypt, agents of US imperialism. They are neither citizens of their own sovereign state, protected by international law, nor citizens of Israel, afforded rights and privileges under Israeli law. The right to be a citizen of a sovereign state is a basic civil right, protected (IIRC) by the Universal Declaration of Human Rights.
Moreover, Gaza is surrounded by hostile states and their access to the sea has been blockaded. They are utterly dependent on Israel for the basic means of subsistence: food, water, electricity and trade, and Israel has been using their control of these basic necessities as an instrument of war.
When a people are being objectively oppressed, they have a right — even a duty — to violently resist. And, so long as they are in fact being oppressed and are indeed resisting, it is not meaningful to criticize any element of their ideology.
People are responsible for their acts, not their beliefs. So long as they are objectively being oppressed, any violent acts must be treated as legitimate resistance. Even if Hamas shouted from the rooftops that all left-handed redheads must die, they are not morally culpable for their acts so long as they kill only left-handed redheads who are actually oppressing them.
Blaming the victims, even a little bit, for their own oppression is as morally contemptible as blaming the Jews of the Warsaw ghetto for resisting the Nazi oppression, even thought there are in fact abhorrent elements of Jewish ideology.