They don't last too long on me either. Well, at least the samples I've used.
That obviously begs the questions of, if their stuff is so high-end and expensive, why does it only last a few hours or so on most people? Shouldn't it last until I scrub it off? ;-)
Creed uses a very minimal amount of synthetic ingredients. Which is both good and bad. You're not going to get that strong alcohol layer that lots of cheaper fragrances have, but at the same time, it's that alcohol mixed with various synthetic musks that makes the smell last so long. The synthetic musk, at a chemical level, isn't a whole lot different than laundry detergent (which is some pretty strong stuff).
Since Creed and lots of other nitch/high-end fragrance makers try to stay away from those sorts of things, they can't use the tried and true ways to prolong scents using synthetic ingredients.
It's not that synthetic ingredients are a bad thing, lots of my favorites (and some fairly pricy bottles) are made from synthetics, it's just a decision that Creed made to stay away from it.