If they are bringing jeans in order not to have to carry "additional clothing"
I think what is meant is that carrying suits and sport coats takes up space; or requires a separate piece of luggage to keep them reasonably unwrinkled. "Lighter" meaning less luggage. Jeans on the other hand can easily travel folded up in a suitcase.
Want to know a secret on how to keep jeans looking good? Turn them inside out and then roll them up. That is how we stored our dungarees in the Navy and they would look almost as good as being ironed.
This is what Carnival has been getting on the comment cards, dress code enforce it or drop it. They just about droped it. Last several years it's been going this way. No big deal, I would rather be compy to at dinner.
I remember an episode of Miami Vice called "Lombard" where a character named Stan is appalled that he and another officer are not allowed in a fancy oceanside restaurant because they are improperly dressed.
Just then, Stan sees a man walking through the place in tennis shorts and asks the host, "Hey, what about that clown? He's in here with shorts on."
In a very arrogant way the host says, "Yes, but they're designer shorts."
So maybe the cruise line has designer shorts in mind?
I wonder how the new dress code will effect the upscale dinning, the one that charges a little extra? I would assume that the old dress code will apply there. Many have already said they would not be bring their suits. Will they have fewer guest? Not too many of us will bring a suit to pay extra to eat!!