Art, the ICZN does recommend against giving related species the same
specific name, like the two nesiotica in your beloved Epitoniidae. But it
does happen, sometimes because a researcher is unaware of the other
species, sometimes because he lacks imagination or doesn't care, sometimes
because the second species was originally placed in another family and not
thought to be closely related to the first. You are asking for far too much
of ordinary humans. Think of how many people share the same first name:
Somehow we manage to distinguish Joe Smith from Joe Brown.
 
The situation improves when someone writes a monograph on any one group.
Think of the immense labor required to monograph the Epitoniidae and get
all the names straight. Is it reasonable to expect a researcher with a new
epitoniid to perform the same work just to name one new species? If the
Epitoniidae are on a par with other groups, then you have had to discard
about one-third of the proposed names as homonyms or synonyms. Have I
guessed right?
 
Andrew K. Rindsberg (as far as I know, a unique name)
Geological Survey of Alabama