The whole term is just nonsense.

A state has three defining features: A territory, a people and a government. Anyone who claims the right of Israel to exist should answer specifically which territory, which people and which government.

I have yet to see someone able to specify these in a way that does not involve forced displacement of Palestinians and justifying other crimes according to international law. And if someone refers only to the territorial areas according to the UN accords, then the next step would be to condemn Israel as a brutal opressive regime, that is illegaly occupying and trying to annex territories that they have no right to.

Finally there is no part of international law that gives states a right to exist. People have a right to exist and people have the right to sovereignity that they can exercise through a state. But as long as the current state of Israel exists it is denying this right to the Palestinians. So anyone claiming a right for Israel to exist is claiming support of crimes against humanity and denying millions of people their rights.

Oh and something that just crossed my mind too. While Israel gets a right to exist and is German "reason of state" because of the holocaust, other people that were just as terribly tortured and murdered by the Nazis did not and do not get the recognition. Queer people, people with disabilities, Sinti, Roma, Communists. None of them received proper reparations and acknowledgement by Germany. The jewish people are abused as a token to claim having bettered and learned from the past mistakes, while other Holocaust victims were and are continuously discriminated.