The instant someone makes that accusation, I disengage. I’ve learned the hard way.
People think that calling someone antisemitic (or anti-Muslim) is a great debate tactic if you’re trying to put your opponent on the defensive and derail the conversation. There’s a major difference between criticizing a government/organization and general bigotry, and they know that perfectly well, but people who want an easy, emotional argument don’t care. They’re not interested in details.
Same goes for most critics of Israel. They don't want to listen because they don't care. They already have their made up facts to parrot, even if they know little of actual history of the region.