Good point Rev., it does make a bit of difference from one cruiseline to another.
I've noticed in just the last few years, the dress codes have becomore more lax or casual. I think in part, from the airline restrictions, you can only pack and carry so much, but one or two formal outfits don't weigh that much.. I take half the pairs of shoes I used to and if I am on a ship that does have the self service laundry, I pack less expecting to do at least clothes once during the week, does save on the packing, along with mix and match.