Recently NewScientist published an interview of linguist Alexandra Aikhenvald. Here are some excerpts :
"Imagine how different politics would be if debates were conducted in Tariana, an Amazonian language in which it is a grammatical error to report something without saying how you found it out - as Alexandra Aikhenvald tells us its speakers tell her. Tariana is in danger of dying. With each such disappearance we risk losing insights into different ways of thinking."
"Why is it important to preserve these languages?
First, to learn about how people communicate and how the human mind works. What are the categories that are important enough for people to express them in their languages?
If these so-called "exotic" languages die, we'll be left with just one world view. This won't be very interesting, and we'll have lost a vast amount of information about human nature and how people perceive the world.
Second, without their language and its structure, people are rootless. In recording it you are also getting down the stories and folklore. If those are lost a huge part of a people's history goes. These stories often have a common root that speaks of a real event, not just a myth. For example, every Amazonian society ever studied has a legend about a great flood."
"And there are so many languages to work on. A dictionary means that the language is not completely lost and it empowers those who speak the language to preserve their cultural identity."
Aikhenvald also thinks Finnish may be the most difficult language she had come across!