my point is that they think they're anti-nationalist but they still default to nationalist thinking. when discussing the global south, so many people here still insist that the west is somehow free and democratic while scary and different global south is oppressive and autocratic.

Depends. Nationalism is progressive in liberating colonized countries from oppression, such as in Palestine. I don't support nationalism in the abstract, but sometimes in the particular if it plays a progressive role. I still support communist movements more, but nationalists can be allied with against colonialism, neocolonialism, and imperialism.