The Hamas rockets have killed few because Israel has spent its time and money and human capital in development, including the education of its people, the construction of schools and businesses that can develop and construct active defenses, and the construction of air raid shelters as passive defenses. The Palestinians have spent their time and money on their charter's stated primary goal, destruction. (Well, they *have* constructed something - not hotels for their miles of Mediterranean coastline, or housing and safety for their people, but tunnels to sneak into their neighbor's territory while their neighbor was letting them alone.) While refugees in Israel become immigrants, generations of Palestinian leadership have manipulated their people as homeless refugees for three or four generations, with the additional disadvantage that their so-called bretheren will not take them in.
I completely agree that many Palestinians who do not want trouble, who would just like to live and work and feed their families, have suffered for the sins of the activist leadership. OTOH if that activist leadership hadn't started shooting rockets, nobody would be shelling them back; and if the rockets weren't positioned amongst living quarters and marketplaces and UN schools, then nobody would be shelling back at those positions. For the average Palestinian, it must be like the average suburban American realizing that a house down the block has been taken over by a drug gang and become a crack house, and there's nothing one can do as an individual to fight them because they'll kill you or your family, and the eventual police shoot-outs with the drug gang send bullets flying through neighbors' windows. Only a thousand times worse. They are at the mercy of the people THEY ELECTED, who in turn pushed out an earlier generation that did not serve them any better.