i think people try but it just looks so obvious that they're trying...
e.g. Jennifer Love Hewitt
Kate Beckinsale- who has frequently referred to her (well maybe not frequently), saying she's for example going for a "rock Audrey" look---i think that was at the MTV awards some time ago...dressed in a black dress with hair up like a bee's bonnet--- going for the Breakfast at Tiffany's look.
That's the look most people try when they're attempting to go for the Audrey look, which in my personal opinion is missing the point and is the reason why they just look like they're copying/trying too hard.