Bad ratings is what causes shows to get cancelled. I didn't mind No Ordinary Family myself, but the show's characters were too generic and I think too much of the show was spent on family matters, like in an ordinary family. The ending of the series was taking the series in new exciting directions, but I think it was too late by then. I think it kind of went through the same phase as Heroes, it was a show with a good/interesting premise but didn't make the most of in it's first season which is crucial to it's survival. (but then you have shows like firefly that get cancelled anyways because of not enough interest).
Btw, Julie Benz is the hottest milf ever.