Atleast Gloria's romance isn't as creepy as Judy's in DA, where you could sexually assault her as soon as you met her, even though she's supposed to be your daughter. Like, Judy and the MC get slipped a drugged that makes them uncontrollably horny - the same drug that ruined Stalla - and by the end of the game this somehow turned into a romance.
What I don't like as much about Gloria is that her dialogue almost makes it seem like not pursuing her is the bad outcome. I know her and the MC share a mental connection and wet dreams, but she always seemed to be uncomfortable with this. Then she suddenly wants to jump on the MC's dick to lose her virginity and is so very disappointed, when you tell her no, that pursuing and not pursuing her almost feels equally bad.
The romantic buildup is much better handled for the other LI, especially Katie and Ellen. It almost feels like Gloria is the intended LI you're supposed to go for, but it's just so handwaved. It's weird that it happens so late in the game, when she's already established as the little sister, as you said.
I agree about Judy back in DA, but not about Gloria. IMHO the game does a good job setting up Gloria's scene in Chapter 10; she may be inexperienced compared to the MC, but she is an adult (both by age and more importantly by the hand life has dealt her). It's not unreasonable for her to take charge of her own sexuality and ask the MC to sleep with her. I think it's played with the right level of ambiguity, too. Whether this is the MC taking advantage of a young girl in a stressful situation or as he's trying to offer some human comfort in a cruel world mostly up to how we perceive the MC's mindset - which feels appropriate for a noir cyberpunk story.
At the risk of sounding like a broken record, I think the big problem that hurts Gloria's path is the way those dreams in Chapter 9 were handled. Gloria is effectively an observer caught in the MC's sex fantasies, which is a sketchy concept at the best of times. Yes, Gloria implies she may have enjoyed the experience in the Ellen dream, but that only happens after the dream is over, which is too late for my comfort. And the Victoria dream is
MUCH worse, since Gloria's response after waking up is bordering on revulsion - even if the MC stopped the dream ASAP. Blech!
It's the way those dreams were staged that causes most of the problems, IMHO. If they had done a better job establishing that the dream was a fusion of both the MC a
nd Gloria's fantasies, it would have defanged a lot of the squick factor and allowed the two characters to begin dealing with their feelings in a measured and open way. That would have been a much smoother transition to Gloria making an overt move on the MC in Chapter 10.
Sadly, the opportunity was lost. But at least the material in Chapter 10 pulls off its half of the deal (again, IMHO).