FYI, they don't indulge in criticism of the State of Israel, they deny the right of Israel or any Jewish State to exist. No, these people aren't anti-Semitic. Anti-Zionism and anti-Semitism aren't equivalent, though as MLK noted, where you find the first, you usually find the second, but not always.
They deny the right of Israel to exist? That does surprise me. (I could see their having a problem with a secular state, I guess. Seems to corrupt a faithful people as a rule.)
But on what grounds do they object? (Rabbinic prohibitions against the hastening of Redemption or what?)