I do agree with you but language is just a mode to exchange our views. Different language can not be credited for different opinions. lets take the example of India, we speak Hindi here and we have people who believe there should be a Mosque at temple's place and vice-versa.
i think if these languages go extinct it would be a great loss to many cultural identities. I would really love to meet people who know their cultural or traditional language because it informs you about what the world was like a thousand years ago when the language first came to origin. It such a wonderful thing to know how your grand parents and their grand parents talked. It gives us an opportunity to get close to them who otherwise have become part of dust.

Undoubtedly in this fast ever changing world one language would be of great help in exchange of thoughts and ideas. And, why not this is our ticket to being global citizens.
Flip the coin and consider this. For a student of history Indus Valley Civilisation remains a tough nut to crack until this day for a simple reason that its script remains undeciphered and the language a mystery. So that, our chances of knowing anything about the great civilisation remain limited. It may not have been put to complete disuse but then successive Aryan invasions and once again the urge to be one world with no communication barriers could have led to extinction of the language.

Language lends distinct identity to the culture it represents. French will always define French culture better than English any day, just as a Punjabi would love to boast about his culture in Punjabi rather than Hindi or Gujarati.

One language sure but not at the cost of regional languages that best define our cultural identity