I don't care about people's opinions. When I say grinding is objectively a bad game design and ask you to explain(if you can) why it isn't a bad game design you failed to come up with an answer other than "because opinions". Doing the same thing over and over again without getting bored is infact called Obsessive-compulsive disorder, and that's a fact.
Honestly, the only grievance I take with this at all is the idea that grinding in a video game is fundamentally bad design. There are plenty of games out there that solely rely on you grinding to improve your skills, mechanically, as a player if you wish to improve, and said game types do pretty damn well for themselves overall, enough to be still relevant gaming experiences now in 2023 as genres. MOBA's, fighting games, and most any multiplayer focused game with a competitive angle to it are HEAVILY reliant on you simply grinding out said game online to improve yourself as a player, and for no real intrinsic reward beyond just playing the game for its own enjoyment.
Naturally, I understand that doesn't exactly apply here, albeit it can to an extent, but seriously, OCD has nothing to do with enjoyment of doing what you might subjectively consider to be fun or on the flipside a repetitive and monotonous task. In fact, its pretty much the opposite, in that you typically find yourself doing irrational things and patterns out of a sense of fear, anxiety, or simply lack of an ability to embrace change. Obviously this is somewhat simplifying it, but OCD fundamentally is built on destructive or disruptive patterns that a person most likely doesn't even want to do, or know isn't good for them, but still finds themselves doing so simply out of a obsessive compulsion to do so, and in many cases, feeling worse and worse the more they stray from doing said act. Again, definitely over simplifying the issue as a whole, but no, its not a fact that Grinding or engaging with a system you enjoy over and over is considered OCD, if that were the case, engaging in something you enjoy like a hobby repeatedly, or better in this example, playing the same game over and over regardless of what it is, as that IS what repetition is, would constitute as you having OCD, and nowhere at all does that make sense.
As for grinding in an RPG being a positive, or a negative experience, it all really just comes down to how much you enjoy subjectively engaging in that system. Its really as cut and dry as that. Most games, especially multiplayer centric ones rely on some level of repetition in their gameplay loops. One of my favorite developers, in fact, basically just outright makes and tweaks the same very system for many of their games in the form of Fromsoftware, and countless people enjoy each and everyone of their titles, some even managing to play the same specific game over and over for either mastery over the game, or to simply continue enjoying it, and you could argue that the games themselves can become somewhat repetitive and grindy in their own gameplay loops. A more direct comparison if any to what we're talking about now would, in all honesty, be MMO's as a whole. Hell, one of my favorites in Classic WoW is one of the most grindy games you can play. I don't necessarily think its improved by its lack of QoL features and longer time to reach max level than pretty much any MMO that's popular on the modern market, but I still would happily prefer to engage with its grindy leveling over, the much similar, grindy end game.
All in all, really all this to say, grinding can be a really poor tool or way to increase a players playtime, but not all repetition is necessarily a grind. In Karryn's Prisons case, I don't even think its a phenomenal game in terms of its gameplay, devoid of an porn naturally, however, I think combined with it, and if you really are one for trying to play the "slow descent into losing to dick" that the game basically is, or just enjoy trying to avoid the inevitable for many without inherently aiming to do a pure playthrough, it nails that niche exceedingly well. Its also one of the few games I can say manages to, at least for me, blend gameplay with its hentai pretty seamlessly, and without it needing to be a pile of you losing to get to that point, while also still having it be a potential con in its own right, even if it doesn't have to be if you choose to simply give in and make a slut build. Doesn't hurt that it also has english voice acting, something that many hentai games simply can't compete with, and a certain polish and quality that similarly, many hentai games do happen to lack. Hell, I even think it does a decent job of providing a world for you to sandbox in, and silly in its own right, even get somewhat immersed in really, all the more improved by things like CCMod, and hell, the fact its even a fairly decently moddable experience is a pretty big plus for it compared to MOST hentai games as well, further adding a bit of replay value alone.
Obviously, I'd still say its a far cry from the pinnacle of actual hentai gaming, namely the vaunted 200-300GB modded Skyrim Install full to the brim with graphics mods, physics frameworks, and all the goodies that you can find on a site like LoversLab, but as a self contained and focused experience it does what it sets out to do quite well. Again, this isn't an attack on you or your opinion, as really, I feel saying the game is poorly made for relying on grinding is, in all honesty, probably one of its biggest common complaints and reason some dislike it. That said, a grind only becomes such when you find it unenjoyable, and its pretty clear that some either don't really mind engaging with said grind here, either due to its windowdressing and "dopamine" from getting a more lustful, or powerful Karryn in the form of levels. HELL, I'm STILL waiting for the day I can just get myself a perfect hentai Darkest Dungeon, and that games WHOLE schtick is endless repetition and mitigation of RNG, and its also probably among some of the most beloved indie games there is despite how repetitive it is.
To further boil this all down though, game isn't objectively bad for one disliking it, or not even liking its more repetitive elements, however, its just as equally not objectively good either, it simply falls into how well the game appeals to you fundamentally on how good it is, and personally, I really don't even find its grind to be all that insane in the grand scheme of things, unless you're just
purposefully attempting to lose over and over to become a full on slut, then yeah, it most definitely does become grindy, all the more if the entertainment provided by the game doesn't dress up and distract from the repetition you're engaging in to reach your end goal.