2 years ago I would have agreed fully - you shouldn't let anyone else decide whether or not to end a relationship. Now that my relationship has been the cause of a split in my close family into those "in favor" and "against", I know better. My graduation has been ruined, family visits are a hassle - can she come, or better not? -, half of the family asks about my partner while the other half pretends she doesn't exist. Should I break with my "bad" family, thereby also losing the "good" half? It is a nice theory and all, but reality is different.
It's absolutely ridiculous to let anyone affect your decision in regards to your relationships. Although personally it is hard if your family/friends do not like the individial and constantly tells you that you deserve better. Although in the end you have to do what makes you happy and if others may it be friends or family, cant be happy for you then you dont need them in your life.