First of all, during the Kutumb times, people were not hooked by the daily teleserials.
Therefore, Kutumb was a fresh concept, with fresh faces and a fresh storyline.
Of course, the chemistry between Gauri-Hiten and the other actors as well, was impeccable.
The concept of hatred turning in love has been shown time and again in the Hindi cinema, but the actors added more spice to it with their great acting which made this concept successful even in the telly world.
And as everyone said, the show wasn't a drag like other current K soaps!