The dojin culture and even just the material culture surrounding ownership is just a wildly different mindset (good memories right now of buying a game online but having to walk over to Family Mart to pay for it on a kiosk so I could actually download it).
The existence of the dojin comic scene nurtured through spaces like the Comic Market existing as a force of energy that exists in tandem with but not parallel to the professional, corporate industry has given the dojin games scene a healthy, mutually supportive character. People care about the health of that scene in a way that Euro-American scenes just don’t.
But, yes, I think it’s absolutely true that there’s less get-rich-quick mentality there. Very few dojin circles are trying to make anything like a living off what they do. My understanding is that most of them take what they make from their works (made in their hobby time, apart from their full-time work) to pour back into buying other dojin creators’ works (I’ve talked to at least one person who does this and have read about it in multiple articles).
(Not sure I buy the greater diversity of genre line in dojin spheres, though–it’s different and possibly more diverse from what you see in commercial indie spaces outside of Japan, but I don’t think it’s actually more diverse from what you see in the broader English-language indie scene on platforms like itch (and even paid dojin works are usually only liminally commercial))