
It can work no matter how that is approached, all that matters is the emotional journey. I mean just look at the first game or even some instances in TiTS. Helia, Marble, Urta, Kiha, Kiro, Tessa, Paige, etc. all have the ability to fuck before romance, but that's not all there is to them. We get to know things about them and do things with them in a way that feels natural towards building a relationship with them. As long as you take the necessary amount of time and effort to properly pace what you do with the character, I think any of them could work romantically. The problem with this game is that people just instantly fall in love with you with no real set-up. You don't have to put any work into it and that's just not how relationships work, even just when it comes to getting into one
I'm fine with Bianca. I never went especially out of my way to repeat her events or anything and I unlocked all her content without any real hassle. Having a character you need to work for and actually has standards is also fine to me since it actually helps characterize them. That's not to say she's done perfectly or anything, but I do think it's not as big a deal as you make it out to be.