| Americans (I'm one) seem to have an incessant need to shorten words and phrases to the minimum required to get the point across. I'm not sure if this is related to the incessant speeding-up of our culture, sheer laziness, or just ornery anti-Englishism. Automobile becomes autocar becomes auto becomes car. Macintosh computer becomes Mac immediately. An Intel-based PC running Windows becomes a Wintel Box. Aeroplane? Nope. Airplane? Sometimes. Plane, usually. Entire phrases aren't safe. Is that okay? becomes OK? This is in contrast to other cultures' slang (not all of course). Take Cockney rhyming slang; it typically turns one word into a two-word pair that rhymes with the original word.
In extreme situations, this can hypertrophy into the American Acronymization Reflex (AAR). | 
