I don't know if this message will be placed in the right thread. I didn't get it to my email, so I had to read it through the archive. Anyway, this is a response to Alex Brollo's question.
The fact is that people are reluctant to contribute images to the Commons. This is our observation for Israel, and I think other chapters around the world have similar observations about their countries.
The Hebrew interface of the Commons is not easy to handle, and English is a foreign language to most Israelis. The number of license tags is huge, most of them are irrelevant to the Israeli user. Communication with the Commons' administrators is often impossible due to the language barrier, and the need to place a description template, which is actually a code, is quite frightening to most technophobic people, and there are plenty of them.
An localized interface makes uploading images much more friendly. The users can see only the the licenses relevant to them, read them in Hebrew, communicate with a Hebrew speaking team etc. The fact that the localized interface is dedicated to Israeli history and to the region's views is very helpful for PR. It is easier to convince people to contribute by saying: "your country needs you - contribute to the heritage of your own country" or something like that. We often limit it even further, and call upon people to contribute to their city's or village's heritage, because this gives a lot of motivation to contributors.
Teachers and instructors feel more comfortable to view the images with their pupils via a localized Israeli interface in Hebrew, so this way we can have better exposure to the Wikimedia projects.
I think I've brought here quite a lot of reasons, but I could probably think of some more.
Dror K