I think you mistake my point. I understand why the existing subscripts and superscripts are incomplete (frustrating as this may be), and I’m not arguing that they set a precedent for adding the rest.
What I intend to argue is that the Unicode block “Mathematical Alphanumeric Symbols” is an exact analogy and precedent for adding multiple styles for use in a field (mathematics) where style lends meaning. Further, that it would be not only helpful, but entirely consistent for unicode to add a new block of superscripts and subscripts for all the latin and greek characters because these are commonly used in mathematical notation.