I know this might not be possible on current ships, but on future ships I would get rid of all mid-ship dining rooms. During the day when the dining room is closed, you have to walk up/down/around to get through the middle of the ship on the dining room decks. Yes, you can sometimes cut through the dining room, but when you can't it's a pain to have to go out the way to just to go from one side of the ship to the other on the same deck.
This is why I love the Spirit class so much, there's only one dining room and it's in the back!
If this isn't possible, at least allow us to cut through the dining room at all times (except maybe a half hour or so before dinners, and during dinner of course).