From Earth: A More Subtle Take on Figuring out an Alien Civilization

Normally, in games, alien cultures seem to be designed to be convenient, rather than plausible. Why is it that everybody but Hutts and Wookiees speaks English, regardless of the planet of origin or species. Here on Earth (only one planet) we have only one species using language (that we know of) and we haveĀ 6,909 living languages.