I think there are a lot of factors to English being used so commonly..
First, you can blame the US for extreme expansion/franchisment/Californication over the last 30-80 years (depending on who you ask). A lot of the Westernized culture in a given place got there on the back of a technology, product or service which the given place was deemed at some point in time to "need." Less so, it seems, does a dollop of Western culture get to a place because it was actually wanted there. It seems it most often arrives by the same routes that are taken by things entering the US that read "Made In China."
Second, and secondary to the first point, there is a higher business demand for English - but that is only because of the first point and related to the third:
Third, while English is not easy to learn and master, it is easy to breach as a student, and to begin learning. IMHO as a native speaker - English can handle a lot of wear-and-tear. It can be abused, misused, and still carry across its original intent and meaning. I think it's very popular because of its great pidgin-ization potential. While it's not glamorous, it's often done that foreign businessmen (in the case of my line of work many of these are East Indian) will learn only a handful of English words, no conjugations and no connective words; and though as I say it's not the most aesthetically pleasing conversation, nonetheless they will use this as a working knowledge of the language and do business in the US - and make money! - with little more linguistic savois-faire than that. I imagine if I went to Russia with my (as yet) sloppy spoken Russian, I'd be a particularly noticeable anomaly - but with English-speaking business extending through different foreign channels, it's quite the norm.
That being said, I think in the long run it's bound to change.. Good questions arise from examination of this issue: does the most common trade-language chosen end up being the one from the richest country? (I hope not, only because I am a poor speaker of Chinese.)![]()