I'm the only "cruise bible" I go by. IMHO you have to go back over a dozen years to think about the food on the mainstream cruise lines being even consistently good. Dining Room food was rarely exceptional. I do believe service was universally better then.
Aside from other changes, the cruise industry has grown at a rapid pace since that time, and even finding staff who excel at offering great service is a chore, simply because of numbers necessary to fill staffing needs on all the ships.
They could improve their training programs to demand better quality from their staff, but there's expenses that go with that.... even presuming you find the people with the right aptitude.
It's not all about simply improving the quality of the ingredients.
Aside from all that the standard cruise fares were all well over $1000 for a 7 day cruise in even an inside cabin, balconies were closer to $1500, if not higher.
Today, it's not difficult to find balcony cabins for $899 (or less) for a 7 day cruise.... and that's including the taxes and gov't fees, as well as the accelerating fuel costs.
The economy dragged after 2001, then went into the tank in 2008. The industry has done pretty well, can you imagine how things would have gone, or will go, if fares increased 40 or 50%?
Frankly, though service can vary with the luck of the draw on the service team you get, I don't find the food on today's cruise ships, that bad at all.
And if I want a slightly better meal I can pay that $25 extra for my meal any time I feel like it.
Yet, other than NCL, where the variety of cuisine in the alternate restaurants is the draw for me, I find food in the regular dining rooms most often qualifies as very good.
On the other hand, I think entertainment is better on ships than it ever was.
Great restaurants on land are also, as a rule, much more expensive than they used to be. You can get a very good dinner for maybe $25/person. But, you generally can't find a great meal for less than $50.
One has to look no further than their own grocery bills at home to realise how much more expensive food has gotten.
In my view it's really a silly arguement. Mass market ships are feeding the masses. The masses are interested in inexpensive vacations.
Those who want better have the ability to pay to upgrade the experience on the more upscale lines.
If the economy ever fully recovers to the levels of the 80s and 90s, leading the customers base to be more affluent, and confident enough to spend more, I would imagine the current business model would adjust to that.