Unpacking this a little...
Point 1: The Antizionist movement is full of unexamined antisemitic tropes, canards, and other pieces of anti-Jewish hatreds; blood libel, well poisoning, world domination conspiracies, and various other pieces of classic antisemitism are all alive and well in the movement.
Point 2: While there are many, many, many legitimate criticisms to make of the Israeli government, most people within the Antizionist movement don't bother to educate themselves on internal Israeli politics and problems, but instead reach straight for a maximalist stance of "Israel needs to be destroyed", often indulging in those above antisemitic beliefs as they do so.
Point 3: Most significantly, there is no accountability and no internal policing within the larger movement. There is no large scale pushback in the Antizionist movement for making it safe for Jews in general, only isolated voices (often indulging in antisemitic statements in the process, ironically), and only for those Jews who are willing to debase themselves into tokens for the larger movement. Even then, that acceptance is so conditional that literally the Jewish token pointing out antisemitic tropes being used by their fellows is enough to have their acceptance and safety revoked, which is something I've seen happen online multiple times, and it's honestly something I'm scared about happening at a protest. Being blunt, I'm pretty sure it would turn into a lynching if that were to happen.
Point 4: As a result of all of this--the rampant antisemitism, the group-think, and the desire to delegitimize Israel at any cost--Antizionists will label any Jew who disagrees with them as a "Zionist", so that they don't have to listen to the Jew in question. They are to be ignored and destroyed, just as Israel is, per Point 2.
Point 5: And since there is practically nobody pushing back within the movement, and there is an overreliance on antisemitic beliefs and conspiracy theories, combined with a desire to delegitimize Israel... all of Jewish history, religion, culture, and society is looked upon with suspicion and an urge to redact Judaism to fit the narrative that is desired. And there is no braking mechanism to stop that. Not in the movement as it currently stands. There is nobody willing to stand up and say, "That is going too far. We can't say that. That is bigoted and racist against the Jewish people." Because, to the mindset common in the movement, there is no such thing as the Jewish people.
In essence, there is no way to keep the Antizionist movement as it currently stands to eventually--and likely quickly--looking at a Jewish prayerbook or Torah Scroll from centuries past, and say that it needs to be destroyed, because it uses Hebrew and mentions "the Land of Israel".