My guess is to prevent (or at least, make it much harder) tampering with the fragrance. It would be nice though. 100ml of most of their scents is just way too much as they are so strong. As mentioned in my signature, I really want to pick up a bottle of Memoir Man but don't need a full 100ml, and yet the 50ml bottle is as you said, not really worth it. *grumble grumble*