Fact: Gazans have just as much right to armed self defense as the Israelis do.
Fact: Hamas, by Israel's own numbers, does a better job at avoiding civilian casualties than the IDF does.
Fact: people who hand wring about Hamas are just classists. They view killing someone with a bomb dropped from a plane as morally superior to killing someone with an AK 47. Their moral judgment in the validity of violence is primarily a function of the income of the person committing the violence.