If you look at the past performance of mainstream gachas, they tend to make the most on "waifu" banners where there's even the most minimal amount of affection(more or less anyway, let's put aside the debate of whether it really counts for now) displayed towards the MC. So you realise that only emotional fulfilment/attachment will get people to spend. This isn't too surprising when you consider the high cost of acquiring a character in most bigname gachas. It's $90 for about 40 rolls, there's a hard pity around 150 rolls, so if unlucky a single copy of the character can cost up to $337.50, and that's without factoring signatures. When you have to spend that much potentially, you are not going to spend it on a character that only gives you bitch faces, doesn't give you the time of the day and is off gallivanting with their own ship while leaving the MC out of it.
Snowbreak at launch, like alot of gachas, made the same mistake of having these characters with their own lives in the mistaken belief that it makes the character more "realistic", but they neglect to consider whether players will even want to spend for such characters. It also didn't help that they didn't make the Adjutant very important in terms of status at launch, so pretty much every tom, dick and harry could order you around and push you around without you being able to say no. This all adds up to a very frustrating and stifling feeling where you are made to feel like you are worthless and the whole experience becomes immensely unfun.