Maybe because it might make it impossible to photograph close-ups of QR codes without actually scanning them?<p>In the sense that making the default camera app into a QR scanner entails that in a certain subset of use-cases it becomes impossible to <i>take</i> a photograph and not undertake a scan.<p>Whether this is considered an issue by those studying such matters is unknown to me; I&#x27;m just speculating wildly.