Second, the whole world doesnt need to speak the same language for cohesive unification. We just need star trek level translation which doesnt seem so far fetched these days.

Finally, everything comes and goes- the stars, the tide, human life, and language. Have you tried speaking to someone from east Baltimore lately? I havent either, but according to my source, The Wire, they speak a language that would probably be close to unintelligible between people from other parts of the English speaking world.

In other words, I'm not worried about language diversity- whenever humans find the need to express themselves in ways that doesnt fit in the current framework, they find a way.

I think language is a clear representation of culture - your first language directly informs how you see the world.

The world would be a lesser place if everybody grew up with the same linguistic experience.