Kamuo is working on a lot of stuff at the same time. Additionally the way the stuff is animated is not really the "fast kind". You can see the work process on Picarto in either the archives or if there is a stream going on.
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It's not the kind where people just make screenshots in HS then make a gif. Add to that how everything in the game is animated. (There is literally not a single still.) Then Kamuo is working a lot on various animations.
I mean, it's up to everyone whether they play it or not. Whether they support it or not. What I can say is that Kamuo is working a lot from what I see. And he is most likely also earning a lot. But I don't think it's reasonable to demand even more work. But I'm fairly sure that there will no longer have updates without any scenes. Though that's just a hunch.
As for why the game was released without any scenes and took this long is probably because Kamuo already had the Patreon account for the games running, because of the previous game. And also decided not to do any lewds before the whole cast is introduced.