There are several geocoders available for OSM. To say that "the database is inconsistent [and] contains many errors", and then back that up solely with a criticism of one piece of client software, makes no sense.
I've backed the statement that OSM is inconsistent by saying that sometimes streets in OSM contain full name and sometime only most important part (and that makes Nominatim unable to search for addresses).
https://mapzen.com/blog/the-world-is-yours-announcing-mapzen...