Why, though? Again, I can easily see this with, say, Felicity. But why, given what she's learned and how she's developed, is Android? Lin? The story doesn't justify "complete obedience."
I'm very much in favor of the kink and the mechanism, but it would add a lot of complexity to make the MC work for it once everyone is fully immersed in the "slavery is bad" narrative. It doesn't ruin the game or anything, but Runey's very good about layering motivations over existing structures. A Lin who's just seen that much of her history was a lie might not be into super-harsh BDSM for a while. A bunch of characters have already removed themselves from the dungeon (or even dating) when various crises occurred. It's baked into Runey's characterization: trauma means less/no crazy sexy fun time. A character who's been broken/humiliated by the system probably wouldn't be open to both in the dungeon.
I was once in a BDSM-rich relationship with a black woman. There was always — always — a delicate balance and a careful path to navigate. Because I couldn't just bring out the (whatever) and start in. She was very much into those things, but there was a very significant historical and cultural threshold that needed to be dealt with and discussed before she'd agree to, say, the belt. The deep narrative conficts in Harem Hotel are pretty much the same: slavery versus freedom. I can't just start flogging someone whose ancestors were slaves, even if she's into it. The MC can't just start flogging NPCs who are slaves, even if they're into it. It's fine as a "nothing's wrong here" gameplay element in the beginning, but once it becomes the core narrative, it has to be faced and addressed and (if the kink's going to continue) justified. That's all I'm saying.
No, but the dungeon is always optional — there are few significant story beats that require the dungeon — and, at the moment, it's a somewhat mindless diversion. NPCs disappear from dungeon availability at points, and then reappear (ssve for Lin's sister), but no one discusses why they're there or what they do. Runey's been excellent at justifying, say, beach exhibitionism/sex, café (the same), etc. But there are, in the story, legitimate reasons why NPCs might not want to be whipped or drink...well, you know...but might still be into being tied up and vibed. Since he's always adding layers, I think adding layers to the dungeon would be worthwhile. Make me (the player) work to get Maria back to the point where she'll do anything. It can be just another story progression stat point, but it makes a whole lot of sense that not every girl would be up for everything all the time, especially given the overarching story.