A language is much more than a messaging medium. By using language we use our feelings and get emotionally closer to our company.
Language is a major advantage that distinguishes us, humans, from other species. Thanks to language we built civilisation.
Languages also contain piles of history, culture and heritage; which are products of generations over generations of people communicating with each other.
Hence, I deeply understand the desire to celebrate languages.
As a language learner, I have found that learning languages opens one up to different cultures, and lets one express oneself better. Even in his native tongue.