Hoi,
To start of, results from the past are no indications of results in the
future. It is the disclaimer insurance companies have to state in all their
adverts in the Netherlands. When you continue and make it a "theological"
issue, you lose me because I am not of this faith, far from it. Wikidata is
its own project and it is utterly dissimilar from Wikipedia.To start of
Wikidata has been a certified success from the start. The improvement it
brought by bringing all interwiki links together is enormous.That alone
should be a pointer that Wikipedia think is not realistic.
To continue, people have been importing data into Wikidata from the start.
They are the statements you know and, it was possible to import them from
Wikipedia because of these interwiki links. So when you call for sources,
it is fairly save to assume that those imports are supported by the quality
of the statements of the Wikipedias
and if anything, that is also where
they typically fail because many assumptions at Wikipedia are plain wrong
at Wikidata. For instance a listed building is not the organisation the
building is known for. At Wikidata they each need their own item and
associated statements.
Wikidata is already a success for other reasons. VIAF no longer links to
Wikipedia but to Wikidata. The biggest benefit of this move is for people
who are not interested in English. Because of this change VIAF links
through Wikidata to all Wikipedias not only en.wp. Consequently people may
find through VIAF Wikipedia articles in their own language through their
library systems.
So do not forget about Wikipedia and the lessons learned. These lessons are
important to Wikipedia. However, they do not necessarily apply to Wikidata
particularly when you approach Wikidata as an opportunity to do things in a
different way. Set theory, a branch of mathematics, is exactly what we
need. When we have data at Wikidata of a given quality.. eg 90% and we have
data at another source with a given quality eg 90%, we can compare the two
and find a subset where the two sources do not match. When we curate the
differences, it is highly likely that we improve quality at Wikidata or at
the other source.