I think a restaurant is a totally different model than a cruise line because it is something that people consume on a regular basis and it is something that has pricing tiers where if to costs a certain amount, it is a completely different market, and it is something where there is a TON more competition. If a restaurant owner raised their prices above the competition without having something to offer for it, just for the sake of raising prices, then of course people would stop going if they decide that they are no longer paying $50 for a burger that was $15 last week. But if that restaurant raised their prices to $50 and it was a genuine kobe burger, you have just completely changed your target market entirely. There are a pair of local restaurants where I live ... one is casual style with a kid menu and they are still on the pricey side but I tend to go in the off season when they do 30% off entrees and even with generous tip on pre-discounted price, I get out of there for $34 for for two of us... something I'm willing to do for a delicious meal. Their other restaurant is one that the Obamas go to every year on their vacation. I have never been there... it is out of my price range/league and I am not the target audience.
But outside of going to super high end ingredients, the calculus that people make is totally different. I mean, a burger is a burger. There is one local place that makes amazing burgers I think are $11 or $12 and has them for $4 on sundays in the off season. So if I'm gonna eat a burger, I'm going to choose that. Or the bowling alley that has them for $6 on fridays. There is not enough difference between burgers for me to pay twice as much elsewhere. And there is SO much competition, I can get burgers at 90% of the restaurants in my price range on the island.
A cruise line is different. People have a very very emotional attachment to disney, through their films, through the parks, through their legacy (how many people have memories of going on RCCL 30 years ago when they were kids? not many I'd guess. Cruising was not really a "family" thing when I was a kid... I mean, I watched the love boat and I know people did go on cruises but it always seemed to be couples and older people and something completely exotic. It was not something that felt accessible to me or anyone I knew.) But Disney has something no other line can have... Disney. The characters, the shows, the theming (which they do better than anyone else). If someone came out with a well done floating hogwarts I'm sure people would be flocking to that, and paying a premium to do it. I think Harry Potter World or whatever it is called gave USO a HUGE shot in the arm for a park that was kind of flagging.
As with the parks, cruise lines are not a dime a dozen like a restaurant is. There are only a few really and they all are pretty different from one another. They are huge luxury expenditures for many people. Most people will take the time to save for what they want if it won't take forever rather than still pay a lot and save for something that they don't want. That said, there are only a few lines that can compete and with a few of their newer ships if you want a cruise like a
disney cruise. If you want an adult cruise, there are many more options... but that is not Disney's direct competition. People spend a lot more time thinking about their next vacation than they do about their next burger. You can get if disney released a special and you could cruise for $2k in an inside cabin people would not be on autopilot with RCCL... they'd be looking hard at disney again even if they weren't willing to pay $5k for the same thing a couple of years before.