I guess I'll be the nonsensical one for a second...I'm not paying that $$$ to watch some slob eat dinner in dirty shorts that he rolled around in Cozumel all day in (it's bad enough at how drunk some people get all day even on a Disney cruise and then carry their loud attitude to the table night after night without shame)...I know it won't be everyone wearing shorts, and I'd probably even wear some more casual linen shorts with a nice button down, but there will be a huge amount of people will not take it that way. Being a bit formal at dinner is part of the reason I liked my first cruise and if i wanted a relaxed dress code I'd just eat at my house after I've spent an hour in the garden. I can just see how many people are going to roll right off port after whatever sweaty activity they were doing and right into the dining room. I'm sorry, don't want to smell or see it.
I personally like the whole tradition of being a little more formal on the cruise considering I don't really dress up for dinner too often and it feels nice for an evening. I think if you can afford the cruise you can afford a pair of khakis and a button down at least, putting forth somewhat of an image that you care about having a nice, clean dinner around everyone else that has paid thousands to cruise along with you.
