I do believe there has been a significant overall deterioration of product throughout the major lines. Since we relegate our cruising to three companies it is difficult to get a handle on what all the others are doing except by talking and listening to fellow voyagers, here and elsewhere.
It appears to me that all the large mainstream cruise lines have adopted pretty much the same business model now. From a profit motive standpoint it is likely to last. If I were to guess at who is to blame, I would say the two big boys on the block are the culprits, Carnival Corporation and Royal Caribbean Cruises Limited. They have been at each others throats for some years now, pursuing a concept that leans toward building more and more very large vessels. Some of the largest ships are getting close to the 9000 passenger plus crew mark. To finance construction of these vessels huge investment dollars are required. In order to fill these ships most lines have adopted a policy of getting passengers on board for a low initial fee, no sticker shock. Even the more affluent baby boomer market isn't large enough for them, so the demographics of the average cruiser has been greatly expanded.
In order to maintain and increase revenues, charging extra for just about everything is taking place. Except for the basic stateroom and food served in the main dining rooms, buffet areas, pizzerias and hamburger/hot dog grill outlets one pays an add-on fee. The ships function more or less like large floating resorts, with all sorts of premium type restaurants and other eatery venues where additional payments are required, not to mention all the boutiques and multiple retail outlets trying to sell something. There is heavy emphasis on selling ship sponsored shore excursions$$$. Effort is made to steer guests away from independent shore excursion venders, i.e. Woe be it unto those booking an independent that is late getting them back for the scheduled departure.
I believe all 11 of the majors are downgrading their product in most areas. Meaning, less staff and poorer quality cuisine in their main dining rooms. By cutting down the size of, quality of, and service within the main dining rooms and other no extra charge areas, guests are more or less forcibly channeled into this nickel and dime game. I wouldn't be surprised to see a trend away from providing a MDR experience, relying instead on huge buffet areas for no extra charge meals. Think, army chow halls.
Perhaps we are getting a little curmudgeonly in our old age, resisting change and expecting too much. Generally I have always provided positive reviews, it is only as of late I see the dark side of cruising.