The totalResultsCount is included in the search result because it is easy to implement and it has some meaning.
What would be the meaning of a total results count for a find nearby service? The total results count would always be the total number of records in the database. Wouldn't it?
returns 100. I suspect there are more, but my maxRows=100 is limiting the number of replies. However, as I don't have a totalResultsCount (of those nearby postal codes within the radius), I can't detect that this is the case.