You know I hate to disagree with you, 5jj, but I *do* hear people saying it as a word nowadays. Not often, and usually I think it's said with an awareness that it's "wrong". If I had to guess at a motivation for using it in this fashion I'd say potentially speed, and also the factor that the users believe it somehow sounds "cooler", as if the person speaking is so used to dealing with "Very Important People" that they can treat them casually. Vip, when pronounced as a word, certainly has some snappiness to the sound.
I wouldn't recommend pronouncing it like this to any English user, though, as it might well be thought to be an actual error by others, who would be more forgiving of a native speaker's liberties with standard usage - unfair as that is.