This follows the ihra definition of Antisemitism. Canada and a number of countries and institutions follow this principle.
Makes sense. Claiming the only Jewish state in the world shouldn't exist, with the history of atrocities perpetrated against the Jews, is pretty clearly saying that Jews should be killed. That's exactly what would happen should Israel cease to exist as history has shown us.
It's true Israel serves as a refuge for Jewish people, but if someone believes a state was founded illegitimately on stolen land why does that necessitate the belief people there should be killed? Like people who talk about decolonization in Western states, giving land back to indigenous people, they aren't saying the people living there now should be killed, or that there can't be a way of sharing land more equitably.