That doesn't take into account the type of people the girls are and that all takes into account the assumption that the talents would actually hit it off with each other. "They might share similar interests, maybe" only go so far. I don't think the content generated would be different enough from what we already get from the girls that do collab with the guys that people should be frothing at the mouth at the mere thought of them collabing together wondering how they couldn't be collabing already.
Calli, Bae, and some of the ID girls are extremely personable, easy to get along with, and generally do well in collabs. Kronii is just a dude-bro and completely unhinged, which works well with them. They genuinely interacted with and got to know the boys before even collabing with them, though, which let them have genuinely interesting. Ame doesn't pull it off at all, but she is just bad with collabs, in general, most of the time.
There has to be some level of rapport for it to actually be interesting. While Kiara could likely pull it off well enough, Mumei, IRyS, and, to a far lesser extent, Fauna would likely just be awful with it. Mumei would 100% wallflower, like she did during the JP Stars Garctic collab with Ollie and Bae, and with pretty much any collab with someone she doesn't really know. IRyS is barely capable of collabing with people she doesn't know, as well. Remember what happened when she was suddenly alone with Kobo when Calli's shit exploded during their Minecraft inpromptu collab? That was one of the most awkward streams I have seen. She barely collabs, in general, anyway. Though, she has had a lot more, lately.
I also think you misinterpret why Fauna doesn't collab with them. Fauna has made it clear on multiple occasions that she has no interest in seeking collabs outside of the EN, JP, and ID girls, like not even just talking about boys, anyone outside Hololive, as well, be it male or female. I don't think anything interesting would come of it. It is not because of unicorns. Unlike Kiara, who is likely a mixture of the whole cute girls doing cute things and not wanting drama, she genuinely just wants to do the cute girls doing cute things with her favorite Hololive girls thing because she is a huge Hololive fan.
I genuinely think the whole "unicorns are the cause of all bad things" has been overblown, nowadays. The people stirring shit are antis and trolls, not unicorns. There is no expelling people from the community like that because they aren't going to leave. Just go back to the whole "we're not friends" drama. That video has a ton of comments, but the ratio of likes to dislikes is like 100 to 1. It is the same hundred or so retards from 4chan trying to stirr shit.
I also just generally think they would have a collab once, then the novelty of it would wear off and they would lose interest and never do it again. So if they just don't want to do it, it's not a big deal.
Tl;dr -- I don't think we are really missing anything if they don't want to collab.
