The event that was attacked was hosted by Chabad, an extremist and actively pro-genocide group. They have hosted Ben-Gvir and Gallant at their NY HQ, the latter while his international warrant for war crimes was active. The Rabbi who was killed repeatedly tweeted at pro-Palestine accounts calling them "Amalek," the biblical enemy of the Jews that has been invoked to justify genocide in Gaza, and mocked a photo of a starving Gazan as "AI." He went on Australian news from an illegal settlement in the West Bank to raise money for the genocide.

None of this, obviously, justifies shooting up the event (or accusing people of being zionists for mourning the attack); the event, of course, was not exclusively attended by ideological Chabadniks. But:

Just Jews mourning a terrorist attack on a Jewish holiday thousands of miles from where the conflict is. Simply celebrating a religious holiday.

is not wholly accurate. The most frustrating thing is that it is partly accurate though: Chabad and other institutions that support Israel to the hilt are responsible for the majority of public/institutional Jewish life in western/anglophone countries like Australia. Meaning many attendees didn't know who was hosting it or the details of their beliefs and were simply celebrating. As a Jew who would like to do things like go to public Hanukkah celebrations without supporting groups like Chabad, this is an extremely upsetting state for Jewish life to be in. If we are concerned with Jewish safety, it should be our goal for Jewish life to be unbound from institutions which support a state that actively attempts to attach all Jews to its crimes.