There might be no clear answer, but why the glyph set of some fonts is so incomplete or inconsistent?
For example, Minion Pro, which is the default font for InDesign, so it seems to pretend to be a really good font for most of us.
It doesn't have the manicule character (U+261B or U+261E). The manicule is not something really rare, exotic. It is a well known and even famous character that was used in many old books.
Another example is Liberation super family by Steve Matteson (serif, sans, sans narrow, and monospaced), which I use for many of my documents. The fonts are free and they are really great, but look at the following table:
Why 0 and 9 are mostly missing? Very inconsistent and very strange.