Earlier quoted context omitted.
Genocide is already defined by the Convention on the Prevention and Punishment of the Crime of Genocide. There is a big difference between saying genocide is wrong, and saying that anyone dying during a war is wrong. Of course every death is a tragedy, but my expectation is that israel (like any country) follows international law. I don't expect them to be absolute pacifists.
Replace "dying" by "murdered". Einstein called killing under the cloak of war murder anyway, and that wasn't even talking about bombing one of the most densely populated areas with over 1M minors in it. If you need more arguments to stand up, you will never stand up. The White Rose also talked about cloaking cowardice under the cloak of wisdom. It's not a tragedy, it's a crime, it has perpetrators and supporters who…
This is not that different than ordinary laws in normal civil society. Sometimes a death is murder. Sometimes it is a lesser charge like manslaughter. Other times it isn't a crime at all (for example if the person was killed in self-defense). What type of crime it is depends on the facts at hand.
Similarly, carpet bombing a densely populated area would be an obvious war crime. However, targeted bombing (which is what israel claims to be doing), maybe - maybe not. It depends on things like how good the targeting is, what is the expected collateral damage, what is the expected military benefit.
Justice happens when everyone is held to the same standard of whatever the law is at the time the offense was comitted and evidence is used to demonstrate that the perpetrator's actions met the elements of the crime. Yes, those types of requirements are hard sometimes, but that is what separates justice from vengence.