In countries with basically a homogenous-language speaking group? It strikes me as more devisive than uniting. More like "separate, but equal". I understand people like to learn things in their native language but as long as you do have people who speak and can teach in the language that you are ostensibly interested in reaching out to and as long as you have literature in their language...
Is it really necessary or even helpful?
I can see things both ways, but in my area we've got a tiny foreign language group which already speaks and reads english so what group of baffled non-english speaking people are being reached in this way?
It strikes me as perhaps a fun thing, I mean I've always wanted to learn Kung Kalahari Bushman click-speak, but how does that relate to the mission?