I dunno, you'll have to argue with any of the good artists to get what you want out of them and even after you've hashed it out you still have to wait for them to deliver. Art is the biggest time/budget eater of any game, H-games worst of all. But without decent ( and consistent ) art there's a good chance nobody's going to buy your game.
You're actually right about this. One of my side gig projects includes the need to commission art, and though it's clean fantasy art, it's still probably the hardest part because every freelancer has their own work ethic, limits, and specialties. I can only imagine that being worse for h art, and of the kind Monster Girl specifically uses.
However, from my experience the better-payed artists (who have higher degrees of skill and more experience to match) tend to be far more professional with far quicker turnarounds, and if I could afford it, I'd use them even for the minor stuff. Hate to generalize too, but I'm pretty sure we can all agree that Japanese are generally more open when it comes to sexual content given they're currently the prime producers of a lot of fringe fetishes, especially in games, and since he can speak Japanese and is Japanese, I'd argue it would be a bit easier to find interested artists, especially considering the popularity of Monster Girl Quest.
I guess what I'm trying to say is that you're 100% right overall but in this specific case I don't think it should have been all that hard. Erotic doujinshi works are already pretty established in Japan in a way they're not anywhere else, i.e. you ain't going to find a Russian or French or whatever equivilant to dlsite, or at least not one that's really all that close, and the vast majority of ero games out there are Japanese for a reason probably.
There's a ton of content out for Monster Girl Quest Paradox though and MGQ the original is finished, so I'm not complaining... though Paradox gives us insight into some characters in a way I didn't realize I'd like as much as I did (like Promestein) so I'd love for that to be finished up too.
Meanwhile, there are plenty of other projects that haven't realized a single game and have perpetually been in development with zero signs of meaningful progress other than 'trust us bro' that make frankly utterly ridiculous amounts of money monthly from people who have paid weeeeeeeeeelllll beyond the game's final $15-$30 final price point, and for those games, I'm far, FAR less sympathetic.
Not to mention, you would also need to find a programmer if you suck at programming (depending on what type of game you're making.)
Neither original MGQ and Paradox do anything you couldn't use premade and pre-coded modules for, or learn on your own. I'm pretty sure the original was one developer commissioning artwork, and rpg maker is even easier to work with + Paradox mostly uses barebones mechanics, tilesets, and systems the base engine already natively supports. From my limited knowledge based on what I've played, you could probably quite easily teach yourself enough to 'code' either game in a really short amount of time, and in Paradox's case, using the word 'code' might even be pretty generous since you'd only need to know enough to perhaps slightly modify some of the scripts you downloaded.