I think every language is just more than a means of communication. A language reflects the way of thinking of its speakers. It carries delicate and unique ways of expressing a feeling, a notion, a concept or a situation. The vocabulary and grammar of a language is the heritage of perhaps millions of people who lived on Earth. Languages, and especially the endangered ones, should be treated and protected just as Mona Lisa painting is protected. They are intangible pieces of universal heritage. They belong to the all humanity, and not just their speakers.
I hope we start to take them even more seriously and prevent their decay.