Totally agree but if you dont have those or any need of those because you have no allergies or major health isdues or are involved in a mass casualty incident its what the emergency service will look for along with tags and paper.
Why knock something that could help you, is widely used by those that may need to help you and is something so easily done. It may just save your life or get your family reunited with you before its too late.
Or...
Why not point out the limitations of something that cannot be completely relied upon to help you, is limited in reliability to those that may need to help you and is something so easily done (if you have a smartphone)... and which may just fail to save your life or get your family reunited with you before its too late, if you haven't backed it up with a more robust system.