I think there's something in this. If someone didn't have the luxury of seeing Quinn's mask slip in the later episodes in an initial play-through and all they had to replay were her actions in, say, the first three, I can easily see why someone might have decided Quinn wasn't for them early on. A lot of the stronger dislike for the character you see on here seems to be directed at the Quinn of episodes 1-3, to my mind. That might be because some players haven't felt any desire to even play through her optional scenes in episodes 6 or 7, because they've already made up their minds about her.
For those of us who have seen the softer side of Quinn as part of an initial/early play-through it's definitely easier to warm up to the character more quickly, I think. Having said that I've also read a good number of posts from people who have changed their minds about her, from initial dislike, to liking her more. Very few (if any) seem to have moved in the opposite direction (liking her, to not liking her), which tells you something about the development arc of the character.