One of the great things about modern English is that it is bottom-up and open-source. Years ago, the Oxford English Dictionary took the approach of documenting what English is, rather than the French approach of dictating what the language should be. As a result, the language evolves based on how ordinary people are using it. Which is perhaps why the word in many languages for new trends and technologies is often the English word (much to the consternation of the French).
I tend to agree with Eugene Volokh's definition of "what is a word." Then think how different this might be in statist cultures, where a word is only a word when the government says it is.
PS- I acknowledge that this makes English harder to learn for people whose first language is less idiomatic.
Update: Much more here