This is something I have been thinking about as well. You can care for one another even if you don't share values. What is important is looking out for one another and having each other's backs while having healthy boundaries. Even in the sense of libertarianism, who the 'I' is is important. Nothing exists in a vacuum, and (to quote some quantum mechanics) I think the 'I' is a superposition of multiple wave functions of the people around you and those caring for one another. You pick up things from people who influence you, and more so from family, as you learn a lot from those you grow up with(for better or for worse, you don't have any other frame of reference). If you do grow up around an abusive family, I think it is important to learn those anti-patterns and learn those boundaries and choose a family of people around you. IMO, the bottom line is that human beings are social creatures(even the autistic ones amongst us), and those social connections helped the tribe survive in our hunter-gatherer past. Humans are not strong or fast individually (compared to predators in the jungle), but collectively, once we cooperate, we can get far to Mars and figure out nuclear fission and, hopefully, fusion. I identify with libertarianism, and I think one can value family and still be a libertarian. Or at least that's what I tell myself, haha