I agree that it sucks to go into the department store thinking your getting a new bag when the bag could have been anywhere!
However, the 14 day return policy doesn't really safeguard you either. What if someone buys the bag and for 14 straight days wears it out clubbing, to dinner, to school, to the grocery store and then returns it? As opposed to someone who has it for 2 months who never took it out of the dustbag? Or when they did they just took it to work (as Roey mentioned) where it pretty much sat on a desk like it would on a display shelve?
While I agree with most that it's not fair to the new buyer I like the flexible return policy because...let's be frank, these bags are expensive! I better like them if I'm spending this kinda money. It's good to know that, within reason and with respect to the future buyer, I can return the bag if I am unhappy.
I would never never take back a abused or imperfect bag. But would I return a bag that was sitting in my closet in its dustbag? You bet!