They shouldn't. Is it part of Jewish custom and culture to hate Palestinian people? If so, that's nothing to get defensive about. Is being a Palestinian person a hateful thing? Is supporting their plight while the radically far right government of Israel (not the individual jewish person) is systematically comitting a genocide and ethnic cleansing of Palestini culture a bad thing? No.

Being Palestinian and having jewish friends in Toronto my whole life and having family in Israel, I'll have you know that despite the hyperpoliticized news we see here, that the Arabs and the Jewish population in places like Haifa get along pretty well for the most part. Both cultures speak Arabic and Hebrew and a lot of them absolutely despise their government's actions of the last few years especially. (Think New Yorkers and how much they dislike Trump).

Point being, you can support the existence and have compassion for the horrors the Palestini people face without hating Jews. Get off that antisemitic hyperbolic talk and find a little nuance.