I think it is interesting that the "I just love the ships" crowd is in the majority right now. Don't get me wrong, there is nothing wrong with that, but it doesn't explain why the Caribbean is so slow, or else you would be there at these prices.
Here is a theory, is it because there has been so much negative publicity lately about people going missing, listing ships, rogue waves, fires, etc?
Could it be the first-time cruiser is disappearing? That only regular cruisers are coming back. Have we reached a saturation point in the total vacation market? Or will these cheap prices lead to a whole new slate of first-time cruisers (like what happened after 2001) and this period is just setting us up for another round of explosive growth?