Also because it would have not added much revenue. 100 cabins cancelled. A 10% reduction may have saved say 50 cabins , revenue 50*90% . At say orginal price £10000 per cabin £450000 extra
10% off the remaining 300 cabins 10%*300 at £10000 = £300,000 loss
So a small marginal gain. If they'd given bigger discount could have kept more people , but a gamble, could have given the discount and only kept a few people and lost on people who would have stayed anyway. .
're the cancelled /aborted/ diverted etc cruises , shareholders may call it insane compensation, but its what they would most likely have ended up being made to pay.
Anyway one other good thing about less than 60% occupancy, plenty of room for social distancing at meals. Should be no close contacts and forced quarantine, with 1038 dining seats and under 600 people, even if everyone turns up at same time