I don't know about the other players, but my issue with Quinn is with her attitude and not her involvement in the world of prostitution and drugs. Quinn is a real bitch, there's a big difference between you being an asshole because someone was an asshole to you (eg MC vs. Dawe) and you just being an asshole because you're a troubled person with a broken family that needs a persona to show being a tough girl (eg Quinn vs. Riona).
Quinn's attitude is just pathetic, it's just someone trying to look strong when they really aren't. When shit hit the fan and she got mugged, the badass girl persona she created was of no use. If the MC is in her route, Quinn can still count on the MC to protect her in the future... but what if the MC isn't in Quinn's route? She has no one, simply because no one would risk it for an asshole like her. Even Riona started to realize that Quinn doesn't know what she's doing.
The point is: Nobody likes an asshole. Quinn can start praying... if shit hits the fan one more time I don't think there will be anyone willing to help her.
I´m not going to defend her attitude in some moments of the history untill now because i think they are forces by her paper in the plot as the "baddest girl" of the "BaddestGirlClub" on town and obviusly she have some moments of pure devil
( succubuslove ) and of course she is the antagonist of an chick mc because Quinn is really no much of an moral/correct person...
and chick route is all about this last..
But i can say what i like about her character.. i think the first thing that comes to my mind is how she dont give a fuck of what people think about her, very important thing nowadays.. , second i would say how strong she looks from outside but in reality how much pain and shit she have to deal with, and how she open about this with MC, incredible leadership skills,no need to talk about naughty side... and even still have time to run the bussiness so her sisters can go throught college without paying ... ( Maya you don´t ) for it.
It´s all about how we connect with the character, thats why this game is that great, many personalities, many options, all people tastes have spoon on this soap.
P.S: Quinn lil titties are something else.
Edit: I would just suggest to DPC an hairstyle change for new update.