First off? Hellcats should not have been canceled. I will forever be angry with the CW for doing so. Not only was there a show they could have let go of in order to give this show a second season, but they advertized it in a way that left most people thinking it was the ridiculous Bring It On copy cat they thought it was. I expected it to be that way too, but it totally blew my mind. The backdrop might have been competitive college cheerleading, but what the show was really about was family and friendship and following dreams. The show should have been given at least one more season, especially with the way the finale went.
Marti wasn't my favorite (that was Savannah), but I loved her just the same. She was strong, spunky, witty, smart and so many other things. She also sucked really hard at relationships. I think it was pretty clear that at the beginning of the series, the only friend she had was Dan Patch, and over the course of it, we see why. She spent most of her time laser focused on school and becoming a lawyer and the rest on taking care of her alcoholic mother. Then when she did finally bond with the Hellcats, she ruined pretty much all of her relationships within, not to mention even Dan took off for a while. It took a few episodes for everyone to get back on the same page.
Somehow in fandom, her talents made her a target of Mary Sue talk, because apparently no one has ever known a girl who's good at school, sports and music. Maybe if I'd stuck around for long enough for her faults to become obvious it would have gotten better, but I doubt it. People would hate on her for hurting everyone, especially Savannah, and as small as the fandom was, I couldn't stick around for that.
I'm not going to justify any of the horrible mistakes Marti made, because they are horrible. I'd have to agree with Dan's dad and say she's a trainwreck. I love that trainwreck, though. I wish I'd gotten the chance to see her grow out of some of it.