It is a lot more complicated than just creating one language that everyone can speak. Language is not made up only of vocabulary and grammar, the whole culture of a nation is a vital part of the language itself. Just think about expressions, idioms, and realia, these all have roots in the culture where the language is spoken in. This is one of the main causes of miscommunication when talking to a person whose native tongue is different from yours. The native language has an enormous influence when learning a foreign language. The reason why Esperanto was a failure is that there was no single culture behind it. Even with globalization, there will still be certain cultural differences between different groups of people.