I fully understand this point of view. I'm not optimistic enough to apply it to Quinn. I see the dark side, I can't get past it. We're in a story, we need drama, and Quinn is a good element for that.I'm going to attempt to explain my viewpoint taking a different approach, because every time I've tried in the past, my point wasn't realized.
In regards to Quinn changing out of love for a guy, in order to understand why this is possible, we have to look at the way her backstory is molding her character. All her life, she was probably only shown true love from her father. Let's say for sake of argument, that her father was taken away (either jailed or dead) while Quinn was still in a developmental stage of her life, such as prepubescent years into early teens. The loss of the one fundamental loving figure in her life, the only one that's ever really shown her any kind of love or kindness, will cause her to adopt a "Me against the world" mentality until she's presented with a replacement loving figure. This is where MC's interactions with Quinn come into play. As far as we know, Quinn doesn't have any kind of romantic/unselfish connection with anyone at B&R. Riona is her closest friend, and the basis of their friendship is a business endeavor. Tommy was supposed to be her friend but it's turning out that Tommy isn't as trustworthy as he used to be with his instability due to drug use, coincidentally caused by Quinn herself.
MC wants nothing from her except her friendship. He's completely genuine in his actions. He doctors her wounds and even offers to help her financially with absolutely no reciprocation expected. This is a completely foreign concept to someone like Quinn. It's taking her by storm and it's going to go one of two ways. Either she's going to hold on to it for dear life, or reject it with every fiber in her being. Episode 7 presented us with evidence of the former.
Where I don't quite agree is with Tommy. They are friends, and it is she who is causing him harm. Having to raise prices comes later, and that's not what hurts Tommy.