Oh, Deep Funk, you have me "banged to rights" there. Caught in the act. Shamed and named (except you didn't know it was me!). I have lived here for ten years, and I still do not speak the local language. 

That is not something that happened by intention at all, quite the opposite. It is a combination of the fact that it is so easy to get by here in English, and a mental block that I could not demolish aged ten, let alone fifty years later. It's easy to get by, but life would be so much better if I were not linguistically challenged.

The language issue is a bit more complex. When the host country or host region (think of the Dutch "Randstad") tolerates multiple languages and even adopts other languages the "learning the language requirement" is less necessary. In Amsterdam you can work and live without ever learning the language yet without knowing or understanding Dutch you miss out on many things.

I am fairly sure the same can be observed in certain parts of India and China. Usually the multiple language regions are also the important trade regions with harbours and financial service providers. There is also the factor that English is the one of the major global trade languages. We can thank the old British Empire and current British Commonwealth for this factor.

For myself I will always try to adapt by at least learning the basic language. The result is rewarding. As a Dutch school kid I spoke French with the locals in Belgium and I was able to find out many things the guides could not tell me. My French was not great but the locals liked that I made the effort and good company usually follows.