One of my favorite campaigns had a lot of family involvement, and I think I only killed one of them throughout. They got good use for plot hooks and providing problems, but they were also a resource, a connection to an area and a history.
The bard in the group was taught the business by his father and had a sister. At one point, the father and son reunited for a tour of the taverns of the big fantasy-opolis where the PCs were. Trouble ensued when an old rival of the father showed up and poisoned the father with some mysterious poison that required an adventure to undo.
The rogue had an extensive family, 15 brothers and sisters and living parents. Most of the family lived in a small rivertown, where they were an important local family. But several of the siblings had spread out to the far reaches of the kingdom. One brother hated him and caused some problems himself, another was a brilliant herbalist, but naive as anything and constantly found himself in trouble with loan sharks and business rivals, another, the youngest, wanted to become an adventurer like the rogue, but ended up going somewhere and not coming back, so the PCs had to try and find out what happened (they eventually rescued him from a Horrible Fate).
The barbarian was the second son of a prominent tribal family and joined the clergy of the Battlemaster and left his native lands, against the wishes of his father and rival brother. In one of the bigger family related moments of the campaign, when things were headed for the epic finish, he returned home to rally his people to go to war, but first had to win his father's support to be seen as having any standing. This required he prove himself to his brother and make amends (which allowed the father to die happy, the only family death I recall). After that, he rallied the tribes and led his people to war.
Point is, if you just use family and friends to "kick them in the backstory", why would they bother?