If I’m understanding you correctly, I am somewhat in agreement. Anti-Zionism and anti-semitism are not the same. (And by “anti-Zionism” I’m assuming you mean criticism of Israel, which is often valid.)
But here’s the thing. These protesters are not protesting in front of Israel’s embassy. They are not confronting Israeli diplomats. They are confronting and threatening individual Jewish students, students who have nothing to do with Israel’s policies.
That’s not anti-Zionism. It’s anti-semitism.
They aren’t protesting against their fellow Jewish students, they are protesting against the university establishment because they want the university’s endowment funds not to be invested in arm makers who can be considered peripherally complicit in the Gaza war.
There’s many Jewish students who are themselves participating in these protest. One Columbia student protester said they even had interfaith seders and other services going on within the encampment. You can be against the protesters but it’s incorrect to label them antisemitic.
Criticism of Israel is fine. Opposition to the existence of Israel is anti-Zionism. Anti-Zionism is almost always antisemitic, since it calls for the destruction of the Jewish state.