and even assumptions about them being hunter gatherers at all are based on centuries of bias and assumptions, with a whole lot of cultural chauvinism and religious nuttery baked in for good measure.

It's based on the fact that we don't observe the morphological changes in plant matter we call "domestication" until the PPNB, after the earliest layers of Gobekli Tepe. Moreover, they have a lot of similarities with other ANE foragers, and there's a distinct lack of both water sources and residential structures suitable for sedentary agriculturalists. Plus, pollen samples from the Harran plain indicate widespread mixed deciduous grasslands during that period, with very low levels of the plants that would later become dominant during the agricultural revolution.

Archaeologists are much better about recognizing the complexity of forager lifeways than they were 50 years ago.