I'm a polyglot and founder and I've also done enterprise work for several large companies, so I'll weigh-in. I think it's because i18n is expensive and difficu

I'm a polyglot and founder and I've also done enterprise work for several large companies, so I'll weigh-in. I think it's because i18n is expensive and difficult. In starting a new project, internationalization means you must include that feature from the beginning. Every word in a dialog box, every button, etc. must be coded so that it can be handled dynamically. This adds a tremendous amount of scaffolding to the program as well as creating a lot of work for the team. Many teams just aren't funded for this kind of work and so they focus on getting the project working in one language only. Often, the decision not to include i18n at the beginning means it will be difficult or impossible to add later, resulting in products that never grow beyond their home language.