Ok, I will try to provide an actual answer apart from all the political circlejerk:

Postcolonial studies have made their rounds in academic circles. While they do provide a good ground for debate on the ongoing exploitation of the southern hemisphere by the northern hemisphere and the consequences of POC living in majority white societies, they do neglect the mechanical workings of antisemitism and antisemitic narratives of "elites controlling the world", those elites might be capitalists, CEO's, "old white men" or "zionists". Therefore they inherently belief in antisemitic narratives without even realizing it, because they just see the world in "oppressors" and "opressed", and the "opressed" can never do anything wrong.

This belief is also a direct consequence of leftist identity politics, where they adhere of a certain image of themselves and just count the reasons why they are opressed (think of intersectionality), so any reasoning falls out of the window because of course opressed people can resist in any way necessary and they don't stop to think about where they might be the opressors themselves in that narrative. And they create identity by othering, in the same way like rightwing people would do it. It's another way of categorizing people and society in "good and bad", and they tend to fall for ideologies instead of analytical thought of the mechanisms in society.

A lot of leftists ascribing themselves to postcolonial theories also lack the understanding of antisemitism and it's distinction from racism. They think antisemitism is when german speaking people try to do shit with gas chambers and they don't see or don't want to see the side of antisemitism which are conspiracy theories, hence they use the term "zionist" as an antisemitic dogwhistle in the same way like literally Nazis would do and it wouldn't surprise me if there's a big intersection between Nazis and leftists who would use the dogwhistle term "zionist occupied government" in the same way.

Additionally, a lot of leftists lack the understanding of what "capitalism" actually is, and they think it's just an elite of evil people "exploiting and opressing" good marginalised people, without an understanding that it's a complex societal mechanism that leads to inequality, where people might be forced by those mechanisms to act in a certain way. Again, they open themselves up to antisemitic thought without realizing it, because they fall for the false idea that antisemitism is not a problem of society as a whole and just an idea of literally Nazis to create a cohesive identity by othering a group of people.

So in an ironic twist, by trying to "resist opression" they themselves are othering a group of people in the same way to create their identity of being opressed, and in this case it's Israel and jewish people. That's why they latch on to the palestinian cause, because of internalized and unrealized antisemitism and because it's confirming their identity of being "The Opressed" who stick together and can never do something wrong because of course they are on the good side of society.