But… the casino isn’t open during port hours??You're right. And it seems the number of people who don't leave the ship is growing. I had an exchange with a YouTube Cruiser Vlogger. He says the ship is everything to him. He doesn't care about the ports. His priorities are the Casino, the shows and the Extra Cost dining. That explains why he didn't like Disney the one time he went, no casino.
I’m sort of getting the same way, the destination (at least on Disney) is more the ship than anything else, although I’ll do excursions in new ports. I’m sure I’ll feel that way if I do the Treasure next year and just spend time exploring the ship instead of seeing ports I’ve already seen.
(Bit ironic I say that and this year I’m going to Alaska and Bermuda which are both places I want to get off the ship.)