People are emotionally driven. When emotions drive us to do something we will (unconsciously) find plausible justifications for it without realizing we're doing it.

Anti-AI crowd is anti AI. Maybe they were (mostly) happy with status quo and don't like change. Maybe scared for the future. Or any other reason. Went from "AI can't even tell what 2+2 is", to "AI can't even tell whether these simply connected smooth 4-manifolds are merely homeomorphic or actually diffeomorphic after stabilization" without batting an eye. The goalposts will keep being moved and the dismissal will continue.