The thing is how they're presented in story. Quinn is obviously presented to be more sympathetic, with greater depth and hidden motivations we don't know, adding complexity to a character that initially is presented as an unrepentant bully but is slowly being shown different sides of, some ugly, some better. She's also shown to develop a positive relationship with the MC of sorts in the DIK path, which is meant to color our perception of her.
Meanwhile Tommy is presented almost always exclusively through bad lenses - either as your godfather, as a friend, as Jody's stepbrother or as any kind of figure you rely on, he's terrible at it, unrepentant about it and his reasons are almost always framed as selfish, and simply him wanting to indulge himself. The exception to that when he's motivated by wanting the greater good of the Fraternity, even that gets deconstructed later on since he just projects himself on the frat. The only scene where he's presented as positive is when you have a frank talk with him at the strip club by picking the Derek route, and even that doesn't seem to change anything.
The above view goes for both the DIK and the CHICK paths, while Quinn gets a lot better mileage out of the DIK path, where instead of just being antagonistic like she is in the CHICK path, she's actually explored a lot more and has an interesting relationship with you with give and takes. If you don't like Maya and go down the DIK path, using her services, your interests align with Quinn a lot more than not. Tommy has no such benefit.
Thus, while they're both very similar if you make a basic outline for them, Quinn and Tommy end up being presented as different by the story itself and that influenced players emotions and feelings about them accordingly, and I think that's perfectly fine. It shows DCP made a good job at directing how you should feel about the characters he writes without telling you directly so.