The reason it is of critical importance is that anti-Semitism is a cancer and it metastasizes in different ways through IHRA. What are we dealing with now? We are dealing with anti-Semitism in the form of anti-Zionism.
I won't give the whole history lesson, but there's a well-documented history of Zionism as racism, which started in Russia and was propagandized. We've been fighting that for years, because it involves a distortion of Zionism.
Zionism is nothing more or less than the right of Jews to have a homeland. It has nothing more to say about that, other than our right of self-determination. Also, it's not inconsistent with Palestinian self-determination, for example, in a two-state solution.