UKstage,
I agree with some of your statements, but having maintained Seven Stars status for approximately ten years, I, too, am familiar with the gaming industry. It should not be glossed over that 85% is a horrible, horrible payback. If even just half of the machines in the ship's casino are at 85%, that's a massive benefit for the house even with scattered better odds in the mix. You yourself mentioned in a prior post about video poker not having a good pay table; let's be honest, the pay tables are worse than even bar tops in Vegas.
Just like other people's losses don't show how good/bad the paybacks are, neither do your wins. Many people here tell stories of losses at the ship's casino; there aren't too many wins. And most people talk about wins more than losses. As you mentioned, no one knows the payback on the slots, but we can see them on video poker and they are terrible. I don't see the casino giving bad odds on those machines and good on others.
NCL posted a loss this last quarter (Q4 2022), and they are looking for revenue everywhere they can. It wouldn't be out of the realm of possibility that they had tighter than normal machines. Just look at the diminished services NCL is doing in other areas on board (i.e one housekeeping visit per day) and also implementing the highest service fees in the industry. It's just not a far-fetched idea to think the machines are heavily weighted towards the house.
Finally, the thought you dismissed as "nobody would play" if the odds were terrible just doesn't hold water because 1) most people have disposable income on vacation, 2) most people don't live in an area where they can gamble so they will play no matter the odds 3) most don't know how to look at pay tables or play for that matter, 4) NCL doesn't need Whales, they just need a steady stream of casual players, 5) compulsive gamblers do exist, and finally, 6) NCL has a captive audience, especially for those times/days with nothing is going on around the ship. At least in Vegas if you don't like one casino, you can find another.
I, for one, am more disciplined than that, I don't play on-board at all. Seeing the video poker pay tables tells me all I need to see about the payback.