I think the "lack of success" was just an easy explanation to tag onto why he quit the game. That is a lot more cordial than saying " I had a meltdown and rage quit" which is what happened. Quite frankly, he just killed his development career. People aren't going to trust him after this, if he ever comes back. Would've been better for everyone if he just quit coming to this website, which caused the rage quit, than to just abandon the game because he got mad at people asking dumb questions.
I think you're right, he rage quit but people don't rage quit like that without there being other issues at play.
However, so what if people don't trust him. Trust him with what? He's suspended his billing and deleting his Patreon page. He's not asking anyone to trust him. And there's nothing to stop him coming back as a different name with a different game. And no one would be any wiser. He's not really lost anything except maybe $100.
But what we've lost is a developer who engaged with his audience, was a regular visitor to this thread, helped people and was seemingly wantong to become more engaged. I didn't know he had a discord until MasterBaitor mentioned it but if he did, he didn't when I was a patron (before his summer hiatus). If he comes back he won't be as engaged.