Why not gnat Ada in gcc?

[Richard Kenner]

    Not really for GDB.  I can count the number of external contributors on one
    hand that existed before we made a repository available on sourceware.

Are you counting the number of people doing development work on GDB
during that period or the number of those who made attempts to merge
their changes back?  I agree the number of the latter were small, but
the number of the former was far larger (and included a lot of large
"players", such as Wind River and HP).  With Ada, there's no evidence
that there are people working on it at all at this point.