Barad’s agential realism has recently been evoked as a theoretical viewpoint for science education and science education research in approaches that emphasize the role of materiality and matter as a key aspect of learning science. Barad’s agential realism is underpinned by their specific ways of reading quantum physics, its interpretations and, in general, contemplations of the quantum nature of existence. Agential realism is an ontological as well as an epistemological (onto-epistemological) metaphysical position that strives to dissolve the boundaries between subjects and objects, and leaves little room for traditional subject-centered epistemological views (like constructivism) of learning. A closer look is warranted at how the quantum physics underpinnings of agential realism, which are clearly very important for it, appear in its current applications in new materialism within science education research. This critical commentary claims that, in such a context, the conceptualization of learning and educational phenomena derives little if any advantage or practical utility from the quantum physics-inspired metaphysics of agential realism; only metaphorical talk remains. Consequently, we need to be aware of the limited power and plausibility of the quantum-inspired contemplations contained in agential realism if it is adopted as a theoretical viewpoint for science education and science education research.