Hoi,
I totally agree with Frederico. The search functionality for other languages is not seen as strategic at this time. This is because the flaws are seen from "our" perspective and the benefits for "our" readers are not understood.
When we promote the use of the multilingual search capabilities of Commons, a meaningful reference is the support Google provides in finding pictures for a language. The results are not great. It follows that the benefits are not based on what you/we experience but on what our readers experience.
When we promote the use of Commons for other languages, a teacher may add labels in THEIR language to the search item that is important in the curriculum for the students. When one teacher adds them for his class, all other classes and schools using the same curriculum will benefit. When someone adds the "depicts" statement to a picture, it can be found in every language that has a label for any picture with that "depicts" statement.
Such an approach is a Wiki approach ... please consider this approach.
Thanks,
GerardM