I feel for Inu, one of the few creators I constantly make sure to download, haven't disliked a single one of their games yet. But yeah changing a mindset is hard especially if they are a perfectionist and Inu sounds like their a perfectionist (I don't mean this in a bad sense). But they wont see how good the overall game is because there's always something that could be better in their eyes, which mean the games they make don't drop in quality but Inu probably won't be satisfied either because of it.
This is a common feeling with creators of anything. You work hard on something and then, one day, you see someone else doing something equally, but in your eyes, it looks way better and it frustrates you. You push yourself to the limit and try so many different things, but it feels like you can't reach the other people with your abbilities. This is the frustration he feels. How do I know? Because I suffered from this as well when I tried to draw and it didn't worked. It felt like I didn't move on, but stuck on the spot. For some reason, and not adding Inui's bad health as well, this naws on him. I can actually understand him, but I'm unable to help him, since I don't know the answer myself.
But sometimes, it is rather more healthy to just walk away from what you do and get a clear head and get a better focus. But then you lose time and for him, this is unforgivable, not only because he uses this DLsite-Patreon-Thing for support. He doesn't want to let people down and give them the best quality for their money... it is a neverending vicious circle with no escape from it than... to quit and move away. That is what I did and I'm not very proud of it, because I wasted like that so much time and energy
I wish I could help him and tell that giving up is not the solution, but the opposite of it. But I also know that he won't listen, because he is stubborn when it comes to these things and won't listen once he made his opinion. But then again, if this is really his wish, if he really wants to quit the game making scene, maybe we should respect that. After all, if you pressure someone into a corner, that does not help either.