There is a huge difference between helping HOT's and DIK's avoid worse fallout from her deals and going out with Quinn to track down a junkie who stole drugs from her so she could recover and sell them.it is not even difficult to imagine how MC could end up involved.
the traffic concerns the HOTs, therefore Sage, secondarily also Tommy and therefore the DIKs, in addition to the Preps and the Nerds
of course MC would not intervene to solve Quinn's problems and allow her to expand her traffic, but to close the matter without casualties or serious damage
MC is a hero and hero never knowingly and willingly help a villain achieve his or her goal! Because let us not fool ourselves... Quinn is a villain in this story. She may not be a main one, or even the most important one but she is one none the less.