Both involve the killing of innocent civilians based on their racioethnic group

This is reductionist. You need to wipe away of the context of a white Jewish supremacist apartheid state vs the context of being scapegoats for the nazis for your position to make sense.

Also settlers aren't civilians, settlement is part of an extended military campaign of genocide.

Yes. Still, they give both context to saying “death to Israel” because they prove that the statement is being used in a violent way.

Violence is justified against settlers, violence isn't justified against an oppressed ethnic minority. They are distinct things.