The Wiktionary's contributors are highly interested by such data because the Wiktionary projects deal with words from languages spoken at several places on Earth. For example, the French language is spoken in France, Belgium, Switzerland, Canada, and a lot of African countries (Algeria, Morocco, Tunisia, Mali, Cameroon, Ivory Coast, etc.). There is currently a lot of content on the French Wiktionary about the French spoken in France but less from Canada and Belgium and far less from African countries.
Knowing how many contributors come from these countries could help target efforts to structure a community of a few contributors or to try to recruit contributors from countries where few are present.
This example can be extended to the main Wiktionarie projects for which languages are spoken in several countries (English, Spanish, Portuguese, Dutch, Russian, Arabic, etc).