Might be based on Arthur C. Clarke's aphorism, "Any sufficiently advanced technology is indistinguishable from magic." Ray Kurzweil uses this as a major motif for "The Singularity is Near" about how Harry Potter can be rewritten with all magic replaced with "advanced" devices with handwaved theoretical feasibility explanations. A more specific issue than sci-fi vs. fantasy is the "hard/soft" sci-fi delineation.