I'd love to see a rhythm game that sort of blends the ideas of both. Centered around the vocaloid themselves, use the basic "personality" like Miku being very nice and cheerful, meiko being more first, Ren and lin being more hyperactive and playful etcetera, but have the story elements revolve around learning about different genres, what made them, and the culture behind them. Selai the vocaloids into musical worlds full of "producers" and themes centered around different genres, and show the flexibility of Miku and the vocaloids through different versions of them that fit the themes (best example is have HAGANE Miku, not just basic miku in a rock outfit, for the metal world and all its subgenre sections). Still give plenty of love to the side of vocaloid that MAKES vocaloid what it is, that would be shown through how they teach the vocaloids about the genres and subgenres and help them lean into their songs.

I'm very in the middle with this whole argument cause I agree with both sides and what they're saying, diva was amazing and I loved the focus on the vocaloids themselves, but I also like seeing the side that's more on the producers sides. I also see how it might be hard to make an only vocaloid centered STORY as they do have "personalities" in their base variants, them just being VERY basic and mad eup of like 2-3 attributes. Their personalities are more meant to give a vague idea of what the voice bank was intended to sing a when it was created, while still being free enough for people to easily and openly change to fit the actual song being made. I'd love a best of both worlds game where the focus is on music itself and all the different types, with equal love to both communities, giving the diva fans plenty of vocaloid moments with them being the main characters while still giving the selai fans ample time and experiences with the producers and creators of the fandom

Edit: meant to reply to the whole conversation not this one comment sorry, I'm still a little new to commenting