[jschulenklopper]

> Why is there no codepoint for GREEK SUBSCRIPT SMALL LETTER ALPHA?

Could it be that (quoted from that Wikipedia page): The World Wide Web Consortium and the Unicode Consortium have made recommendations on the choice between using markup and using superscript and subscript characters: "When used in mathematical context (MathML) it is recommended to consistently use style markup for superscripts and subscripts."

Inconsistency remains though, since the Unicode standard defines characters for full superscript Latin lowercase alphabet except q, a limited uppercase Latin alphabet, a few subscripted lowercase letters, and some Greek letters.