Stuart Turton at Den of Geek put up a bit of an article examining The Sarah Connor Chronicles’ failure to obtain a third season.
His first assertion is that the show is too introverted, with complex philosophies and character relationships, and a creative team that doesn’t ease newcomers in mid-show. I guess that to a degree, he’s right. There’s a lot to pick up (not as much, as BSG), and without a connection to the characters, you might feel it’s not worth the effort.
Personally, I wouldn’t blame you. As Turton points out, the Terminator name implies robot fights and big explosions. TSCC only occasionally delivers those, and they’re not always very spectatular. Also, the “navel gazing” portion is often in a (to my mind) needlessly self-indulgent format.
I wouldn’t blame any viewer for giving up on the show, and when viewers do that, so do networks.