I see your point, and I agree it's not ideal for a character to completely disappear from the game if you don't actively romance them. Honestly I haven't seen this so far (maybe because I haven't tried to actively shun Carol, which seems the only way you could stop her romance totally) - I mean, I have zero interest in Rachel and have so far had to constantly reiterate that in my choices, despite several of them forcing me to take a pretty douchy selection to avoid being ensnared in her romance. Roxy also doesn't interest me and while she isn't being given romance options anymore, she's still present in the story. But in some ways, a character disappearing if you make it clear you're not interested makes sense too, so I'm not sure that's so big an issue. Carol throws herself at you pretty hard, if you try to friend-zone her, I could see her walking away...