Everybody who speaks English can communicate with anybody else who also happens to speak English. You can talk, you can mail, you can read books written in English by others.
Sure you can invent your own language, no big deal. You can even make somebody learn it and then talk to her.
But most prefer easy way and speak XML, I mean English.
[Well, technically speaking majority on this planet prefer Chinese anyway].
My guesstimates:
Chinese is a family of very different languages.
'chinese' is not spoken by 50+% of the world population.
Many people speak english quite well as a non-native language.