I imagine part of it is that the penalties for cruise cancellations are subject to much higher penalties versus other products and the penalty schedules are quite complicated. So many variations based on days before cruise, cruise length, concierge, GT, covid policy etc. Would be a bit of a headache to program the system to generate the correct penalty. What happens when someone cancels at 11:59pm before their PIF and their internet is slow so the cancellation goes in after 12:00 and they lose their deposit? Or when someone cancels a concierge cruise to book a new one without realizing they could have kept their deposit if they moved their booking rather than cancel?
I remember in spring 2020 cancelling a stateroom I had booked for my in-laws because of covid and on the phone they warned me several times that I’d be losing 50% of the fare (they eventually reimbursed me retroactively after they cancelled the cruise)—I knew that penalty would happen, but I bet a lot of people don’t pay attention. Maybe they feel like it would be to much of a hassle both in terms of programming the system (and making changes whenever they temporarily relax the penalties) or a customer relations hassle when people get mad because they didn’t read the fine print.