While there may be value in preserving those cultures. What tends to happen is outsiders say "We want to preserve that interesting way of life in case it's usef

While there may be value in preserving those cultures. What tends to happen is outsiders say "We want to preserve that interesting way of life in case it's useful to us oneday. Hey you natives with nothing better to do all day, why don't you keep using it so we don't have to? You won't need English in your remote tribe." Then the poorest people in the world end up lumped with the huge task of maintaining a language for the possible benefit or mere academic curiosity of others. Instead, they could just learn English as children and gain access to greater opportunities in the global economy.