paulchinnz:
That's because when it's stored the right way up, the tasty flavouring sinks to the bottom, so you get less flavour with the crackers at the top. By opening the bottom, the coating redistributes throughout the crackers, leading to a more enjoyable culinary experience.
The correct way to get the flavour powder properly distributed through the crackers is to to pound the inner plastic bag thoroughly with a rolling pin - then give the bag a good shake prior to opening.
Sometimes with potato chips workers in the distribution chain - like supermarket shelf-stockers - do this for you manually before you buy - which is very thoughtful of them.