We cannot have a reasonable discussion when people are making arguments that are beyond ridiculous - how can we take anyone seriously who effectively argues that no matter how excessive Israel's response might be, all the deaths of Gazans are the moral responsibility of Hamas.
That, franky, is inane.
Imagine a scenario where Canada is a mighty military power and the US is much, much weaker. Now imagine that some American terrorists, whose base of operations is in Manhattan, sneak into Canada and brutally murder thousands. Imagine that Canada then firebombs Manhattan, arguing, legitimately, that the terrorists are hiding out under various Manhattan skyscrapers. And thousands and thousands of innocent Americans die.
Would you then argue "it's the fault of the terrorists"?
We all know the answer.