Paul, I suspect a good amount of the hand wringing regarding Carnival indeed comes from those travel agents (mostly not identifying themselves as such) who have found their commissions cut by Carnival.
I'm not loyal to any cruise line. I've sailed HAL, Carnival NCL, Royal, and Celebrity. Never had a bad cruise. As has been said before, they are all more similar than different.
Some emphasize one feature over another, but in general terms, this is what I've observed...
-Royal has the biggest ships
-NCL has the best entertianment
-Carnival has the least amount of "nickel and dime" venues (as you pointed out) and the best food
They all offer good service.
I remember when Delta Airlines started to cut out commissions on booking their tickets through travel agents. I had an agent who said she would book me on anything except Delta. Short sighted on her part, as all airlines cut commissions and she lost not only my business travel business, but my vacation travel business, too.
Carnival may have cut their commissions, but there are other ways to make money in the travel industry.
I'm Sailing the Breeze in two weeks. I'm very much looking forward to that. I expect I'll get a beautiful ship, with great service, good food, fun entertainment, stopping off in pretty locales. That doesn't sound bad in my book.