If you have someone oppressing you and taking your territory eventually cutting you off from the outside world in what is often referred to as the largest open air prison in the world and you have the capacity for violence is it unreasonable to expect you will use it? If the oppressor then slams you, hurts you very badly, and lies about what they will do to the rest of the world are they really supportable?
To be clear, I think the leadership of both Hamas and the Israeli government are acting for their own interests to the exclusion of the interests of their people. Both are attacking civilians, both are committing war crimes, both are increasing the cycle of violence. One of them has the backing of the west in a significant way and is oppressing the other, stealing land and frequently killing civilians, the other is ineffectively fighting back. Both wrong, one more powerful and more genocidal, maybe you could not support either and support the people in both, the citizens who are just trying to survive.