If anyone is a critic of Israel in the sense of saying that Israel does not have the right to exist, then they are an anti-Semite by definition.==
I agree that it is wrong.
Israel as the national state of Jews has to exist. But I think Israel isn't be covered from any critics. No need to call any critism as anti-semitism.
When someone tells obvious lies, like saying it is forbidden for non-Jews to marry Jews in Israel, their anti-Semitism is obvious.
Saying such things isn't "criticism", it is outright slander.