I don't think it reflects on GMMR's family, this is more of a story and intrigue thing. It would also be pretty unrealistic if they were all the same. And they are still very family-bound, like at the beginning of the show all the Lannisters are arrogant jackasses (except Tyrion but he has his own problems, due to being born a dwarf), and the Starks, while all having their differences, are all still very loyal-based people, like their father inspired them.