I've been following this project off and on for a while, frankly this post is bizarre. It seems like he'd been burning out for a long time and AI was the last straw. He goes over how he doesn't like the Touhou games, he doesn't like the Touhou characters, and he doesn't like the Touhou community. His motivation for working on the project seems to some combination of be wanting to seen as a pillar of the community (which he has no respect for), and the financial incentive because his decompilation work is funded by donors who choose what he works on.

There's one part where he goes over how he felt scorned because a remake of a different Touhou game that he wasn't decompiling came out, and people in the Western Touhou community worked on it, but nobody told him about it prior to its public announcement. There's a different part where he's complaining about how some FreeBSD user submitted a PR to fix his Seihou port to build on FreeBSD since the niche build system he uses doesn't have good support for *BSD. He spends a paragraph ranting about how he would never support FreeBSD, then the next paragraph is about how he would have loved to get it working on FreeBSD if the person went about asking for the feature the "correct way", then he says he'd rather quit programming entirely than support FreeBSD on desktop.

I think he saw the project as an obligation that he couldn't get rid of rather than something he did out of passion. There's a section at the end where he goes over how his life will improve now that he doesn't have to work on the project. Notably, throughout the post he calls out by name various people in the Touhou community that he doesn't like, but he never calls out any of the vibecoders. I hope that he can now spend his time doing something that he actually enjoys.